Israel trained it's army to fight counter-insurgency and had trouble fighting Hezbollah.

It's approximately the difference between police work and conventional warfare. Mixing the two jobs in one unit, or mixing the units in one job, tends to be stressful. Loosely, a soldier has to shoot first and maybe ask questions later. A cop has to work in the opposite order and defuse a situation. You can't defuse Hezbollah.

And you can't defuse the Russian troops in Georgia. Although the small wars experts might be of use to the Georgians, as they were to the Afghans not so long ago.

The US military, focused on SOCOM, mixed the immiscible in Iraq. But also think of the Kent State shootings, a case of unfriendly fire. And think of the IDF in southern Lebanon.

The only solution is agility.