What is the intel...?
If Gai caught Jubi Jin Madara off guard (who obviously has superior sensing and reaction), then nothing supports the notion of DMS Kabuto reacting any better. Replace DMS Kabuto with Madara in that very scenerio, and Kabuto is eating a point blank Hirudora. Doubt DMS Kabuto is as durable as a V3 susano'o, but I have no clue what's his regeneration capabilites.
Summoning Manda II off bat would probably solidify a win for Kabuto though. But I think that course of action is circumstantial to the amount of intel given.