Right now we have around 2.5 different sorts of targets. Tanks, cyborgs, and, technically, defenses, but they are rarely used. Well, maybe VTOLs sometimes. So all games boil down to a faction-based approach: "choose one anti-cyborg weapon, [probably] choose one anti-tank weapon, produce them". All we are interested in is enemy's ratios of tanks:borgs and AT:AP. That's what we all have learned. But hey, guys.
- That's pretty dumb.
- force players to research all weapon branches in every game!
We already have tracks, hovers, cyborgs, yellow and green bodies, three body sizes. That's a lot of different sorts of targets, but we never care about it enough to change rockets to cannons in mid-game or change machine guns to flamers in mid-game.
For example, we could make sure lancers are worse than cannons against light body halftracks. Either due to overkill, or due to armor factor, or due to worse modifiers. If this effect becomes important enough, if lancers would have really difficult time dealing not only with cyborgs but also with leopard halftracks spam, we could force the players keep cannons to fight against light bodies and keep rockets to fight against heavy tracked tanks.
Another way would be to buff the HP of cannons and nerf the HP of machineguns and rockets. Then players would need cannons as meat shields and mgs or rockets in certain proportion to deal damage either against tanks or against cyborgs, even though cannons would not do much damage on their own (but upgrading them would still be hopefully useful, with correct upgrade prices).