When properly trained the regulars could be trusted to persevere through a campaign; whereas the militia were sure to disband if kept out for any length of time.
Moreover, a regular army formed a weapon with a temper tried and known; whereas a militia force was the most brittle of swords which might give one true stroke, or might fly into splinters at the first slight blow.
Regulars were the only troops who could be trusted to wear out their foes in a succession of weary and hard-fought campaigns.
The best backwoods fighters, however, such men as Kenton and Brady had in their scout companies, were much superior to the regulars, and were able to meet the Indians on at least equal terms.

But there were only a very few such men; and they were too impatient of discipline to be embodied in an army.

The bulk of the frontier militia consisted of men who were better riflemen than the regulars and often physically abler, but who were otherwise in every military sense inferior, possessing their defects, sometimes in an accentuated form, and not possessing their compensating virtues.

Like the regulars, these militia fought the Indians at a terrible disadvantage.

A defeat for either meant murderous slaughter; for whereas the trained Indian fighters fought or fled each for himself, the ordinary troops huddled together in a mass, an easy mark for their savage foes.
Extreme Difficulty of the War.
The task set the leaders of the army in the Northwest was one of extreme difficulty and danger.