Would Michael have cared if Rocco had said "It's done Mike" but then proceeded to set up a plan which involved throwaway gunmen, distractions and most importantly had Rocco himself nowhere near the assassination?

If Rocco had strolled back in the compound and told everyone to watch the news would Michael be satisfied that the job was done or be silently asking himself "I thought I sent that guy on a suicide mission. What's he doing back here? Note to self: watch him..."

lol

"When the snows fall and the white winds blow, the lone wolf dies but the pack survives."
Winter is Coming

Now this is the Law of the Jungle—as old and as true as the sky; And the wolf that shall keep it may prosper, but the wolf that shall break it must die.
As the creeper that girdles the tree-trunk, the Law runneth forward and back; For the strength of the Pack is the Wolf, and the strength of the Wolf is the Pack.