What government you have affects what levels of regional & factional (sorry 7= faction not local) MIC you can build up.
This is something I've only recently really gotten my head around (along with the Recruitment Viewer) so I may be off here.

You need a Type 4 government to get level 5 Regional MIC but if you have that government you can only build a level 2 Factional MIC.
Likewise for a Type 1 government you can build level 5 Factional MIC but only level 2 Regional MIC.

As mentioned by Redmeth (& I've only just looked), in the "<path>/EB/documentation/JMRC Building Trees" folder, there are a bunch of .pdf files showing the build trees for each faction, they have colour coded indicators of what can be built with which government type.
These are excellent & well worth investigating

The recruitment viewer says the Scordisci need a level 5 Regional MIC so you're going to need a Type 4 government to get them. (dunno if you can change to other government after building the level 5 & still recruit?)

Hmm, hadn't noticed you can build the Bosphoran Archers in Mikra Skythia recruitment viewer says level 3 Regional MIC so you can get this with Type 2,3 or 4 Government. (I've currently got a Type 1 there so will be changing this)

For Rhomphiaphori you need a Level 4 Factional MIC so Type 1 or 2 Government.

I have no idea how to tell what units need reforms.