That's great, but based on the topic, I understood that it was about fixing the original... and possibly fixing it "in a different way," i.e., not necessarily based on Equilibris.
In my opinion, it's still about the game as a whole, and not about a specific base version:)
Because I don't agree with everything in Equilibris, and if you want, I'll post something on the topic of "what would you change in Equilibris."
And regarding the potion - it's rare to be able to drink more than one in battle anyway, not counting what's drunk before the battle.
But even so, no matter how actively the potion of immortality is used, it rarely decides the outcome of the battle (in the sense that whoever has more will ultimately win:).
As for the main topic, I wouldn't risk changing much else besides the random map generator, in a fundamental way. I think the main problem with the 4th game is the time spent playing it. The length of some battles, the movement of individual units, and so on, add up to those 4-8 hours, or even more, per game. For example, no one will risk playing XL maps online, just as they won't risk playing L maps.

Барон "Vampires"
Отдай свои прошлые сны,
В сомненьях себя обрети,
В бешеном танце душа кружится!
Не думай, что будет потом,
Здесь и сейчас мы живем,
Стань хоть на миг сам собой, слышишь!