This post Is of my own opinion and doesn't necessarily have the same opinions as other hogs.
Through gaming, traditional, miniatures and consoles, I've slowly learned some general strategies that have both helped me in warhammer 40k and warhammer fantasy. Some other gamers may read this post and just nod your head and say "ok... but I didn't learn anything new I haven't already be doing for year." This post is not for you. I just wanted to jot down some general strategies I've used for a while to maybe help out the new or intermediate players.
While this is not stating that if you use historical or real war tactics you will automatically succeed and win all of your games it certainly cannot hurt. A lot lately I've been reading so much math hammer online and people claiming that this list can't be beaten or this list can't beat this list and 'prove' it with math.
Also recently I played in a team tournament where my final round was Me (Ig with hydras and vets) my teammate (ork walker spam) against the other team (mini leaf blower and Mephiston and BA melta spam that all had fnp and fc)We had to deploy first we anchored a heavy flank and then put all the fast units (valks and trucks) on one side. Also spread out a little so we would make the BA player at a high risk for mishap. Now they deploy and put all the Ig on one side and the BA's on the other not wishing to drop them piece meal and risking mishaps. After deployment I moved my two valks flat out back to our anchored flank. This tactic is called a feigned flank. Now were going first and have the full weight of our army against the poor IG player and the BA our almost completely out of the fight. I used a couple of bait and flee tactics on them twice to make sure they stayed out. We proceeded to almost table them. In the after game discussion all anyone could talk about was lists lists lists. It didn't matter that the 270 point juggernaut only killed a truck the whole game and all the other BA only happened to kill a veteran squad and one valk. Between the online mathhammer and that particular battle I was inspired to write an article on very general tactics.
The Battle of Marathon.
At the battle of Marathon the Greek general weighed his flanks extremely well with his best troops and more of them. As his middle started to buckle he closed both flanks in on the center of the enemy that was breaking through the middle and utterly destroyed the Persian army. This is now known as a pincer attack or pincer formation. This was history's first account of this style of combat. While in fantasy this would be harder to pull off, in a game of 40k this very viable. Put your stronger hammer units more towards your flanks and advance the whole army you can either hold in the middle or start to fall back slightly as he advances his army a little and then crush in from both sides. Destroying the middle and putting a lot of your units in a central location which is good as they can support each other. To some extent like chess. If control the center you control the board. While not impossible in fantasy when you reform to smash the flanks of the units in the center you'll be exposing your own flanks and and giving your opponent 1 turn to react before you can connect.
The 300 Spartans
On a historical note the movie and comics are great but it pretty much combined the Battle of marathon with Thermopylae. Also there were 7k Greek solders not just the 300 and a couple of allies that were complete push overs. The whole kicking a guy down a well after refusing earth and water was the Athenians not the Spartans. This tactic generally evolves around putting a unit in the narrow side of a tunnel of terrain and being able to hold it with superior troops. Essentially the same in a video game by pulling the enemy into a dungeon door way so instead of getting mauled and surrounded you can fight one at a time. I think this is a hard tactic to use on the fly as in most games terrain is spread out. In 8th edition fantasy and 5th edition 40k terrain doesn't hinder you as much as previous editions.
Samurai Out Numbered
An old Samurai trick if out numbered was to run away and your opponents would pursue you. As all humans are not equal in every aspect they will follow at different speeds and as you turn back to face them you'll only have to fight them one at a time or kill one and start running again. In fantasy this can only be done against certain armies. (Ones that have a different move value per units.) Also making matters worse for fantasy movement for fleeing, pursuit and charging is more random than ever and also premeasuring hurt this style of play in the new edition. While not impossible far trickier now to pull off. In 40k this could translate into pulling a unit back that's a juicy target for a unit to assault and drawing his fast vehicle normal vehicles and infantry away from a supporting role for each other as their thinner.
The Feigned Flank
This really can be summed up by anchoring a good base on one side and having some fast or cheap units on the other so it looks like your spread out over your deployment but you can quickly redeploy to hammer your whole force against half of theirs. Also it can be used with disposable cheap units to bog down their flank as they chew through units that won't net the points that the units your about to hit with your real force. I use this tactic often. It's my second favorite overall tactic and I employ it in Fantasy and 40k often.
My absolute favorite tactic. I use this in almost every game I play and have a dedicated unit to this tactic in every unit I build. Another name for this and a more politically correct name for sure is a Disruption unit. Basically this tactic is all about throwing a threat right in their face and making them deal with it or disrupting their overall battle plan. "So why do you call it drunk driving LBB?" Simple. Drunk Driving is a bad idea. It's a poor decision. I love these units because more often than not it panics the opponent psychologically or it makes them make a bad move or two. In warhammer Fantasy I use Dark Elf shades with sometimes for an assassin for this role and in 40k I usually use a Dread in a Drop pod with a MM and HF. Its something from turn 1 in the middle of your lines or possible behind you. It deploys after you have already set up more times than not. So it capitalizes on disruption your plans but even more important to me is making you make a bad decision that I can capitalize on and win the game. It's like in chess where your opponent moves a piece and then they move a piece back to its original spot. They've wasted two turns and your in a better position. While this isn't auto win it certainly is nothing but an advantage for you. And please don't drink in drive.
I think that sums it up well enough. While I'm not saying list building isn't important or knowing the math isn't important I do think that is only part of the battle. Dice make up 5 to 10% of the game, List make up 30 % the rest is knowing where and how to stack those odds in your favor to better achieve victory. Deployment has literally won me games. After my opponent deployed and I had deployed I knew it was over before it ever really began. Keep improving your game readers and people that contemplate warhammer list/math go grab some fresh air out of the basement for a while. You deserve it. ;)