For that team to be a reliable revan counter , you need Both zetas on grievous , and the one one b2 and the one on b1. I wouldn’t hold off on the zeta , I made sure to do all 4 on my team before I considered using them against any team really. I began testing them with g11 grev and all the zetas , and it could beat a decent Jedi Rey team. So that’s a milestone to look for.
Once you have the zetas , focus on getting grev to g13 or at least 12. Then you’ll have a reliable and versatile offence team. Prioritize grev over all the others in the team.