The problem I’m having with a bunch of modern RTS games is, lack of clunk. Clunk can be good!
I think the clunkiness kinda make BW works. It adds for better mele vs ranged dynamics and increases defenders advantage.
However, I don't think we should try to replicate this in modern games. I think we should try to add skill-expression, defenders advantage and ranged-vs-melee dynamics work in a different way.
One thing that became so clear to me when I experienced with the Sc2 modding is that melee units needs to be fast. Ultras should imo be faster (and smaller). Zealots should be faster and legspeed removed. Broodwar gets that right.
For some reason Stormgate decides to go in the opposite direction with the Brute being the worst defender.
But besides generally making them faster, it is imo easier to make ranged units work. To create diversity for melee units we would have to explore with different types of abilities. But I also think abilities should be simple too use and not take up too APM.
I want players to spend the primary part of their APM moving units around as opposed to ability-spamming so it's a tricky balance. Thus, abilities should reward "movement-based" micro as opposed to existing for the sake of existing (looking at abduct as an offender here)