More difficult quite probably, but more complex I do not think so. Essentially we are doing the same thing in conventional warfare as we are in COIN except with emphasis on different parts of the system.

Digressing slightly, but on the difficulty side; I wonder if we put two evenly matched opponents (in terms of military capability) against each other whether thay would find conventional ops any more difficult then COIN ops? Of the 'find, fix, strike and exploit' elements; in COIN none of them leap out as any more difficult to do then in conventional ops, less I think 'exploit'.

With COIN the insurgent has an assymetric advantage in 'find, fix, strike., exploit' but we tend to regard conventional ops as easier because historically in the mid-late 20th century we've had the advantage in 'find - strike'.