Well I build type 4's rarely, usually with a specific sort of r/p house rule in mind. Eg I usually have an independent gallic kingdom in Ankara and Tylis, or a Skythian one at Olbia. Once I have them I allow myself to hire the appropriate mercs (their king has "lent" me some troops), so I try to grab an Hai city befoerwe I hire Georgian inf, or a steppe city before I hire HA mercs etc. Also I can raise local allied forces as police/garrison and elites for my FL, and build merc generals once the MIC is maxed to lead out an "allied army" (usually to go hunting for a similar kingdom to found, eg Ankara wants Tylis, Olbia wants the crimea or Tanais to found another type 4).

So I build a few clients, and fewer mercs. I have a secret wish to build an army of generals, say 4 Verrix, 4 germans, 4 Nomad generals and 4 Hellenistic or Eastern mercs for a nice balanced force. Do they get 2 hp like FM's? I forget.