Hello @JbuckBuddy ,
I am considering rule 6.1 which exlpains the difference between nations that share a turn but may not attack together (USSR/CCP and USA/KMT) and those that share a turn and can Attack and Defend together as one nation (British Commonwealth).
In this case, it says that Turkey :
TAW 1.3 Successful Influence: When an Alliance has four Influence Points Turkey will become an independent player country run by Italy (if Axis), France/Free France (if Allied) or the USSR (if Comintern) regardless of who paid for the final influence. No further influence may be attempted.
The NRS adds : “Order of Play: Turkey is played with Controlling Power”.
I may be wrong, but I understand these to mean that (in case of Axis control) Italy and Turkey will share a turn, but not that they may Attack and Defend together as one nation like the Commonwealth.
If both Turkey and Italy attack the same territory during their turn, I think that you would have to resolve both battle separately and not pool all the attacking forces for the purpose of combat.
Finally, rule 9.1 : “The attacking player decides in which order the declared combats are resolved”. So there could still be a can-opener effect.