Regarding the map's difficulty. There's a mod like that – TE, where the guard towers are simply enormous (utopias are resting), and the typical game duration is 4-6 weeks. What can we say about maps with ordinary guard towers, where you can grab relics almost in the first weeks.

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In theory, it might work somehow, but increasing the penetration will shift the "balance" in its favor.

Any strong perk in one place or another shifts the "balance" in favor of those strategies where it works best. I don't see any problem here; it's just the way it is, and when choosing a perk, the player also chooses a strategy. SA is definitely not something you see in every game.

Essentially, you're saying that you personally don't like the emphasis on the super-perk's effect on penetration because such a perk probably doesn't fit your play style very well. But no one is forcing you to take it. If I constantly level up warriors, I won't demand that unnecessary skills for me, such as wizardry, chaos, or summoning, be removed from the game. Or, for example, SA for mages. What if my play style already involves getting a large number of spells, so I won't get much benefit from learning all of them (I already have a lot). Should SA be replaced for mages?

Regarding hero development, I don't know what "fully developed" means, but levels 16-20 already allow you to fully implement any necessary tactic (as seen in RTA). The rest is just an optional addition, a game of accumulation (you can take more, but there's not much point in it).