I often play on S difficulty at 200% against 7 opponents just for fun.
In most cases, I WIN, and in the remaining cases, there is always one computer that I leave for last, it levels up (while I take care of its allies), and then I'm done for... In principle, if I lose, it's ONLY to ONE!
And on large and medium-sized maps, it's simply IMPOSSIBLE to LOSE!:)

I completely agree!!
I haven't dared to play on S difficulty yet, but I often play on L difficulty (with all computers in an alliance) against 7 computers!! at 200% WOG.
The computer starts attacking in the 2-3rd week!!
Buildings:
Stronghold, prefecture, castle, and then it depends on the resources available.
Tactics:
For the first 2-3 weeks, don't stray too far from the castle!! Collect resources.
I level up a hero-artilleryman!! (I've tried others, but they get destroyed :( )
In the 2-3rd week (when the computer attacks), I go to the castle and skip turns!!
Over time, I level up to approximately 1000 for a Demigod of Towers. And then I go and destroy everyone, not worrying about my "home" nest