Most AF3+2 set procs are a 10% chance or appear to be. Not cited, but from hearsay I believe MNK, NIN and DNC have all been found to be 10% with 5/5.

It's hard to test THF and WAR especially because it only happens during TA or DA respectively.

Although if you can't cap haste with 5/5, it'd never be worth it. (And without atma on THF you can't)