While Krillin did need Gohan's help to fight a 23k Goku, one should note that they initially held back against him, and it's not like either of them performed bad against him on their own. Plus, I can see Krillin take the edge with either Solar Flare or Kienzan.
Against Monster Zarbon, however...unless he's smart about using the aforementioned moves, he will probably suffer the same fate as Vegeta.
Gogeta (Broly) VS GTVerse
* Assume SSB Gogeta (Manga-Scaling) = SS4 Gogeta
* Manga-scaling
* Gogeta cannot use any form above Super Saiyan
Where does he stop?