Cast on Melee Kill + Dominating Blow = Does it work?

If the build is Resolute Technique then Cast On Critical Strike is not an option.

One can conceive of builds that use DB+Culling+CoMK+??? as a "last hit" 4L using other skills for actual damage output.

The OP is not asking "is this idea optimal for all situations", or even "is this effective", just if it works at all.

My favorite low lvl comk is detonate dead. Does wonders when you use something like ground slam. As soon as 1 mob dies the rest basically drop as well. Give it a shot, grab a cheap 4 link and put cast on melee kill, ground slam, detonate dead, (life leech or some extra dmg is good here)

Ground slam is not a spell. But detonate dead sounds like a great idea...