8-player Smash

I'm just wondering this...
WHY is 8-player Smash bad?
HOW does it affect the AI?
WHAT changes happen to the AI?

well, its in a number of ways actually.
1. it makes the amiibo agressive as far as i have experienced atleast.
2. It's pretty much a reset while still stay at level 50 option
3. because there is 8 players, amiibo could do damage to the other 7 players, which in turn can make them spam aerials, bad moves, etc.
4. the only good thing about it is you can get rewards using your coin army amiibo (Coin army is amiibo that fights to give you rewards and for that reason only, it is recommended to leave these amiibo vanilla (vanilla means no equipment fed) since there is really no point in giving them equipment).
this is all I know...
I hope this helps!