Younger Toguro destroys Yammy.
Don't know the percentages, but Toguro up to when he intimated Yusuke into going to the DT would wrestly evenly with base Yammy. Yammy still had the second strongest base Hierro (was hurting a power puncher like Yoruichi with it) and it was stated in the databook that the destructive power of his physical blows are the highest among the Espada (supported when he knocked around Bankai Ichigo with one arm).
R1 Yammy stops at 100% or 120% Toguro.
And R2 Yammy easily crushes any form of Toguro.
@supernova7005: It happened in the anime. So it's a clear win for the anime version of Toguro at least. But even if it didn't destroy anything in the manga Hiei's dragon of the darkness flame is still way more impressive then Nnoitra's cero and Bui was able to take it.