I am a big fan of small detachments. I normally use 3 blocks of infantry (GS, spear & sword) of 19. Characters will be the 20th figure. The sword & GS each take 5 handgunners, spear take 5 crossbow (this unit normally does not advance). I then take 2 detachments of Free Company of 5, or 1 of 8 (if I run out of points).
I have found that most armies ignore the Free Company, but I would rather have them shooting at 5 point troops rather than my pistoliers, artillery, or main units. Same thing for my missile detachments.
I have also found that the troops that my infantry faces often don't have ranks. Fast troops like fliers, chariots, monsters, swarms, fast cavalry & and units of 5 knights, so it doesn't matter so much if there are less than 5 troops in the detachment.
There is always the old argument of which troops make the best detachment, but I go with TVI logic of 2 swings for 5 points apposed to 1 for 7 points.
Shotzie