As a lot of you already mentioned, we just need the option to define separate tactics for defensive and offensive phases of play. It's not only about different formations (which should be mandatory) but also about individual and collective behaviour. That'll be hard to do as it would require some sort of artificial intelligence editor, but I can't think of easier ways to fully control your team.
There's lots of example everyone can possibly think about for his team, so why not go through some of them?
- I want my players (and anyone of them) to press viciously and tackle hard immediately after losing possession, as long as the ball is still near them and the opponent still isn't in organized offense mode. After a couple of seconds, they shall resort into a disciplined defensive formation.
- Immediately after winning possession, I want my players to charge forward as directly as possible, but only as long as the opposition still hasn't taken their defensive lines, i.e. as long as there's a chance to hit them unprepared. If that initial strike should fail, resort into patient probing around the box, playing out of a possession-focused mindset.
- When launcing a counter-attack after a free kick/corner/whatever, I want my Advanced Forward to care explicitly for getting and keeping the ball after clearance (thus playing horizontally), keeping possession as long as my second striker comes from deep (the vertical one), passing into space for him to break through. Basically that's doable now (Advanced Forward/Deep-Lying Forward with lots of Run From Deep), it just doesn't work the way it should.
Now that's stuff you need to get into scripting, perhaps editing AI files. But I dunno how those (IRL default-ish) tactical means are to be implemented via the current tactics interface. That needs more depth and more precise instructions.
Also, some sort of FIFA-style set piece editor would be great. Only to add individual options, it doesn't need to replace all default set pieces. No team in the world runs solely on creative, studied set pieces (apart from Marcelo Bielsa's players, apparently
). Just giving the option to see your own studied set piece score once in a while should be a great motivation and a massive boost to your very own self-confidence.
That's just my ramble. Apart from that, there's only lots of decorative stuff to be improved, but it's fine the way it is.