I propose this.
Olimar can only control yellow Pikmin. Here is why. It is the only Pikmin species with a visible ear structure, the other's either have otherwise ovular heads with no visible ear structure available to them. Those antennae do not count, no animal's antennae on this planet can detect sonic vibrations. Thus the Yellow Pikmin are the only ones with a evolved ear structure to hear anything, so they are the only ones whom could take commands from Olimar.
Also, the Pikmin are dumb as blunted nails. In SSE and Pikmin, the Pikmin do not react individually or at all to an offensive force directed at them unless Olimar give a command. None of them even notice the Giant R.O.B. wake up from sleep mode. This lack of intelligence makes them unlikely to respond immediately to stimuli as it is, and means that their simple-mindedness can be their's an d Olimar's undoing.
Those little claws won't do much either, because of the parka's the ICs are wearing as well as their cleated climbing boots. The Parkas double as armor against the small, comparatively frail Pikmin.
Don't even bring the whole "Pikmin have the strength of ants" thing into this. That means nothing when they are attacking as individuals, even if they swarm, the Pikmin would attack individually of themselves. Meaning that each individual Pikmin would be attacking within that swarm. Each individual attacking Pikmin together won't be able to tear the parka at all.
Also, the size of the ICs makes them many times heavier than 10 Pikmin can hope to hold. 10 Pikmin won't be toppling the ICs with strength. They can just kill those t10 and Olimar is doomed.
Also, who says that the ICs do not take any downtime between climbs? They probably take a climb, wait until their muscles are not sore, then continue climbing. In this, they are not muscularly degenerated.
Those Parkas only make them look fat because they are thick, they are meant to keep one warm in the colder parts of Alaska, Canada, Russia and other icy northern areas that are typically extremely cold.
As such, the ICs are not likely to be muscularly degenerated, if at all, and the Pikmin cannon penetrate their parkas due to not having the individual muscle power to do so.
GG Olimar.