No argument from me, but this isn't something we get to decide. I do want to note that they weren't specifically on the list of available forces, although that doesn't mean we're not allowed to use them.TBH if Asuma isn't willing to deploy summoners aggressively we're kinda screwed. He's already decided to keep the essies at home. Plus Rock will almost always be able to bring more jounin to any assault than we can.
I think the plan still works without one Summoner, but two would be pretty bad. We might have to go with Mari/Akane SCs in that case.