good evening...the current team your having is splendid surely...shisui can be going great with kushina and naruto since he will be giving you a barrier advantage at the start of the battle..however if your enemy auto barrier overcome your team barrier then shisui support benefits will heavily drop down ..at that case he will be useful to control your enemy units i think ...if your searching for a ninja that can serve your team with better support options then i think if you already have gnw gaara then he would be wonderful for this team especially if your having the right breakthrough talents...having gaara on the team will allow you to activate his barrier manually which it will give you a better chance to successfully trigger the barrier to support your team members... as for the mains i think breeze dancer can be wonderful for this team..yet the flower guard talent wont be much useful i think since kushina is already having an immunity to debuffs so mostly this will only be a benefit to your main... if i am not mistaken..wind style enhancement might be helpful to your team...hope this can be helpful to aid you on making your decision...

best of luck..