The problem is that without knowing what type of conflict we are talking about it is too hard to say this or that is a good idea for certain.
And then of course even if you get it right the situation might change... your enemy might adopt a different strategy and buy new weapons based on the systems you have.
Sometimes you might get luck... your enemy sees your formidable ATGM potential and decides against wasting money on MBTs and instead goes for lighter more mobile vehicles. Well ATGMs can still take out point targets at extended ranges so you could modify your missiles from HEAT warheads designed to penetrate 1m or more of armour then perhaps redesign it to punch a fist sized hole in thinner armour and then blow plasma or thermobaric material into the cavity to burn and suffocate the contents... would work on armour and would work on bunkers and buildings...
I think medium and high flying larger drones will be useful for monitoring the battlefield, while smaller drones carried by troops can work down to the squad level in finding targets.
If they can get 152mm artillery shells going 170kms then a vehicle or two around the place should give all weather day night support capability most soldiers crave... being a top attack munition it should be fine even for heavy armour.
I think drones have a role to play but much of the time they will be looking for targets and sharing a picture of the battlefield with various units... and of course marking targets for precision attacks.
Regarding enemy air power... well whether you are using manned air support or unmanned this is something you have to deal with either way.
Having specialist drones designed to take out dedicated air defence systems would be important for drones as it is for manned aircraft... just because unmanned drones are expendable does not mean you throw them away... when destroyed they stop performing their function... unless they are suicide drones of course.