Guide says the min damage for pet is 70%, so if its true, I say reaching 100% rate is a big deal. Crit damage would have synergy because just focusing in rate already gives damage; the crit damage just make said build better. And keep in mind that not only suph has higher rate than sufi, but it can also wear the crit ring(which ends up at 3% dps once rate is maxed, so is a decent ring in general) which means less investment needed