Restricting own indies is bad. Especially when limit is put on snubcraft choice.
While you say they can request, I'd say why should they be forced to?
If you want diversity at first, you can do it by having less restrictions for certain, rarely used IDs such as Synth, Planetform, OSC (+/-), Researcher.
If you change RFP/RM RP, this brings a burden for the future. Who knows who is leading your Factions in one year. All other housforces are free to choose Police/Military of theyr house freely.