-5% or -10%?

[Gargoyle]

Which is it:

Two separated units in a area. Both say -5% due to lack of command.

Group the two units and its -10%.

If the stay ungrouped and fight a battle, is it -5% or -10%?

Or is it they may be encountered piecemeal, so its -5% each, but might fight separately. While if grouped the suffer the -10% but fight together?

I tried to keep this question clear I hope was successful.

[Stonewall]

You answered yourself. -5% for each, but they might not join each other in battle. -10% if together, but all of your combat units will fight together.

[Pocus]

as Stonewall said. You will get a bigger penalty, but at least they are fighting together and not separatly (in some instances), so overall it is generally better to regroup units.

[Adlertag]

So the gaming equation :
(-10%) not equals (-5%) + (-5%)

[Rafiki]

Nah, I'd say you let the units remain independant (so they each suffer only a -5% penalty), but seeing as they are independant, you can't rely upon them helping each other out in a battle.