I took your idea but added a little tweak to it. On the first wave i controlled sukuna so he doesn't attack the enemies. I let them cross the 2nd bridge and put 4 more gojos at the back to chain auto ts, this buys you 600+ more seconds. Just make sure to place the 2nd set of gojos somewhere so it doesnt interfere with range of the other 4 at the front If the 4 gojo at front is exactly in that location, then the 2nd set of gojo should be near the tree on right of sukuna where u placed him
yes but natsu has fire element and it's weak against water. isn't genos a better pick than him since he has lightning element plus he can hit air and elementals