Some thought about the mission/ questions to ask Asuma.
1) We need information, anything related to Rock capabilities in sensing/protecting hard targets in Asuma possession would be useful.
2)Political landscape in Grass would also be useful, if there is some clan in Grass whose Modus Operandi we can imitate while destroying the bride it would be useful, especially if said clan is anti-Leaf(This would tied Grass to Leaf even strongly).
3)RoE with Rock-nin/Grass-nin? Who can we kill? Who would Asuma prefer dead? We can't promise anything, but if We have the occasion, we could also blow the bride when people(for example Rock Nin) are passing through it, making this an Assassination+Demolition mission....or wait and blow the bride when no one is on it.
This would also make the Grass/Rock relationship even worse if we can pin this on Grass.
4)Possible secondary targets? Places we can strike to distract Rock from guarding the bridge? Places we can attack if there is the possibility?
5) Someone to be wary of?(Ex.S-Ranker/High-Jonin that could be there)
6) If deniability is of the utmost importance, he could also order some ninja on a diplomatic mission to Grass, blow the bridge when they are there and then use Skywalkers to survive, then use the incident to take concessions from Grass and Rock for the "failed assassination of loyal Leaf-nin", or accuse another village, for example Cloud, to try and poison the relationship between Rock and Leaf and their "mutual alliance".