In the past, PRX transitioned its roster from CSGO to Valorant. In the scene they were tier 2-3 as far as I remember, mostly T3. Nowadays, with the way the teams are playing, which franchising team would make a good tier 1 team, I am talking HLTV Top 15-20 max.
Let me start first, I think that G2 would be a great fit. They play Valo in a manner that Navi plays in CS, protocol heavy, no definitive superstar, non ballsy and calculated. The only thing is that in CS2 atm there is a dedicated AWPer, and I don't think icy would fit the position, maybe Leaf?