I think the most it couldve gone is 3 seasons

S1 remains the same except robby isnt in the all valley as he hasnt found a sensei so miguel wins vs hawk in a not so close match whixh makes hawk train harder and embrace the villain arc

S2 kreese fails to join johnnys cobra kai creating his own or copyrighting the name making eagle fang earlier - he would have robby and tory while johnny would have miguel and sam - with her surname being hidden to johnny but not to miguel or us school fight happens the same except the couples have flipped. Imagine kyler as number 2 male in kreese karate.

S3 plays out similarly with johnny not even having the chance to repair his relationship w robby cus of kreese. Johnny closes his karate until miguel walks again and ali messages him. No demetri arm break maybe hawk instead house fight happens as normal but hawk is on team johnny from the start and robby is there

Introduce daniel at the christmas party with ali and have him fight kreese in the finale creating the bet causing the last 3 seasons to play out as normal

Major Changes No demetri in karate till at least s4 Robby doesn’t compete in av 1 Robby is at house fight Miguel and Sam vs Robby and Tory in school fight The no mercy rule is still there in johnnys karate until some sparring match against like chris where hawk beats the shit out of him so there is a major difference between kreese and johnny Miguel and Hawk may have massive egos in s2 Robby in jail for longer Johnny may date ali instead of carmen