Here is where the issue is.

Basic math. Say a rogue has a 20% crit chance.

In order to get crits on 6 gcds worth of abilities for a sabo it's a 4% chance (.20*.20) to get the double crit they need blast charges crit + detonate crit 1/25 Chance

In order for ANY OTHER CLASS with 20% crit to get 6 crits in a row (.20*.20*.20*.20*.20*.20), not counting bullseye and strafe it's a .006% chance. 1/15625 Chance

Problem? Yes.

I play a Sabo and I can admit this is a balance problem.