I think this is a common misconception, that the "handling", basically the system that mediates between the player inputs and the in-game outputs, is somehow separate from the "gameplay" and its workings can thus be changed freely with no expected impact on the aforementioned system of play.
I'm being pretentious here in the hopes to demonstrate my main grief, that amateurs like us should not delude ourselves that we're in the known when giving our feedback on game design philosophy.
I would personally just ask to not make a remake out of a remaster, but since both you and Jim Vessella & Co (why people trust the guy that tried to sell them on the "mobile base" of CNC4 being a breakthrough in RTS is beyond me) insist on doing so, my answer would be: only to the extent that it doesn't take away from the game experience.
For example, I argue that the Dune 2 modification 'Dune Dynasty' that (along many "new" rip-offed features) allows the player to select and control the entire army at once, is not only an inferior gaming experience to "games with modern controls", as unlike Dune 2 's successors, it doesn't add more depth to keep the player engaged though a high level of interaction that the game still requires of them, but also an inferior gaming experience to the base game, as there's little for the player to do except A-move in Dune Dynasty in contrast to the "primitive", yet true to Dune 2 's legacy, challenge of selecting and controlling units individually.
Take this from a non-veteran, maybe you lack this perspective, but to me these old RTS games shine because they're a product of their time not in spite of that, their functionality is encoded into their very soul, they only need to be restored not upgraded, just like with historical pieces of a bygone era that can still serve a function in contemporary society. I would even dare to claim it is you who aged, while the game code stayed completely unchanged.
I say, a remaster ought to limit itself to make the game playable (no glitches), compatible (no crashes) and supported (no 3rd party applications required). Balance and customization are concerns beyond remastering that may be addressed only once the project has been finalized and the product reviewed by its intended audience.
If someone's not satisfied that I didn't give a proper answer to the issue at hand, I would like the queue this way: infantry queue up to 5, that's all, everything else still one at a time. It's completely arbitrary, I know, show me an answer that's not so.