Be very careful with that tactic
. I don't know if the computer will do it, but if a player owns the country you invade as an SA, and manages to kill the unit in the capital with guerrilla units or outside reinforcements, he can then disclose that country during the disclosure phase, place one of the new units in the capital, and kill 3 very expensive planes.
A good rule of thumb is to place a unit with more hitpoints then the number given as guerrilla reinforcements. That is, when you disclose guerrilla you can usually do damage in the first turn equal to the cash you get for guerrillas. So when you invade a small the enemy can nearly always do 4 damage to a single target or spread out amongst your forces. So if you stick a full health tank in the capital and there are no reinforcements nearby, you are safe.