If Doffy doesn’t make Luffy turn gear 4, he dies. If Law hadn’t injured him, Doffy wouldn’t have been caught slacking and gotten head butted by Boundman. If Oda hadn’t had Doffy been retarded and try to clash with the King Kong Gun, Luffy dies. The team fight is only ONE of the asterisks next to the Doffy fight.
Stitching made the limitation to Doflamingo's combat power from GK very minimal, if Luffy hadn't wasted so much endurance getting to Doffy and had gone G4 from the start and surprise Organ'd him then Doflamingo would be out.
Boundman is faster and stronger than Doflamingo, the time limit running out in the first round was PIS as Doflamingo was "one attack away" from being ko'd until he recuperated, if Luffy hadn't wasted time explaining his powers and using less effective techniques he would have won, this was plot to show the weakness of G4, to prolong the arc and ramp up the stakes, to give shine to all the small characters etc.
Doflamingo didn't have the choice but to clash, boundman's mobility is superior and he could teleport in front of Doffy and hit him with it if he didn't try to clash and defend himself properly.
If Doflamingo fought in the mirror world Luffy could have beat Doflamingo a lot easier, the wide open area was prime for his stall tactics and pseudo flight, similarly if Luffy fought Katakuri in dressrosa, Katakuri would be at a disadvantage with his lack of aerial mobility.