I've not seen one instance where using a pet, Imp or Observer or anything other than your DG on Will would net more dps than a Sac'd pet, nor are there any actual locks rankings with this mindset, nor is it particularly helpful to your raid. If Rages are lasting the duration of dots, then the rest of the raid needs to step it up. Simple as that. Just make a macro for SB:SS and go to town on everything. You'll have time to MG things aplenty. Evelria(sp?) probably used a pet early in the xpac when they weren't as geared, so that extra boss damage was helpful but that's iffy logic at best.