[SG2] Fire Team Casualties Question, for the Experts

I'm working on a set of fire team rules for SG2. I have a question about
casualties.

When a platoon in a modern army using fire teams, such as the US army, takes
casualties, how is the platoon restructured after the battle? Let's say, for
the sake of argument, that there were 10% or fewer casualties. Do the fire
teams maintain their original personnel? Or are fire teams/squads that
took casualties "cannibalized" to bring up the strength of other fire
teams/squads
that have been reduced by casualties? If a "standard" fire team has 4
soldiers, what is the lowest number of soldiers needed to make a "viable" fire
team?

The reason I'm asking is that the SG2 rule book includes rules for calculating
the size of units as if they had taken casualties. (See "Under-Strength
Units", page 10). It's possible that a squad of 9 soldiers could be reduced
to, say, 6. I'm curious how they would be organized. Would the emphasis be to
balance the fire teams evenly? Or would they operate as one over-sized
fire team of 5 plus a squad leader? Would the fire teams receive transfers
from another squad to build up a fire team to 4 men each, if possible?

On one hand, I can see drills requiring a certain number of troops and certain
types of equipment in each fire team. On the other, I can see wanting to
maintain fire team integrity as soldiers live and train with the same people
in their squads.

My guess would be that if a platoon of 4 squads, 9 per squad (ignoring command
and support elements) were reduced from 36 to 32 soldiers, the tendancy would
be to organize them as 3 squads of 9 (1 SL, 2 fire teams of 2), and the other
5 would form a squad of one SL and one fire team. I would also guess that if
they were to drop to 28 soldiers, they would form 2 squads of 9 and one squad
of 10. But, this is just a guess, which is why I'm asking.