In a way, football is a sport of the mind as much as it is of the body. Football thrives on creating and exploiting space for yourself and for others. A successful tactic finds ways to generate space where there was thought to be none. This objective can be achieved by patiently passing the ball around, by hoofing the ball forward to a big guy, by stretching the opposition until holes appear, by immediately counter-attacking once the ball is won or in a dozen other and distinctive ways. The fact remains that every tactic exploits space somehow.
The match engine of Football Manager is no different than an actual football match in terms of tactics, the key to creating a successful tactic is finding a way to generate and exploit space for your team, whilst simultaneously restricting the space the opposition gets. Every version of the match engine has its weaknesses, a specific tactic or approach that is overpowered, a bit too effective. In FM16 you could score for fun just by launching a barrage of crosses into the penalty area, CM03/04 had its Diablo tactic with the insanely effective central midfielder scoring for fun and in the 17.2 match engine you have another example of this tactical kryptonite; the inverted wingback.