“Applies XXX stacks” is the same as x00% chance to apply. LE doesn’t allow multiple conversions though, so if you’ve had something converted to bleed, you can’t then convert to ignite. Though that’s an interesting question as to why the gloves don’t comvert “native” bleed into ignite for AoD. I assume it’s because AoD is coded in a funky way which checks to see if a mob is in range & applies stacks rather than hitting and applying stacks, hence the wording that AoD takes a % of your bleed chance & uses that.