Yep, this is a real flaw: #poptype only affects the kind of units that can be recruited at that province and nothing else.
However, since I have come to the conclusion that indipendent strength 7 or higher is a bad choice for multiplayer (see reasons below), a common solution to retain random indies while still boosting some provinces is adding some crossbows or tribal archers. Those go along well with most indipendent types thematically and still make a significant difference in the province's strength, regardless of the indipendent strength setting (hence allowing the game creator to suit himself).
(The reason why I do not like high independent strength is that:- I got frustrated of Dom2 multiplayer games where I fought a long time against indipendents and only a very short time against human competitors. E.g. I found the SHEPHERD scenario particularly disappointing, since after the independents I just killed the central AI and never had any interaction with my competiting human players. The fight was tough, but I just prefer to battle against humans.
- it delays the game, shifting emphasize away from mundane troops to summons. With easy independents, mundane troops can become really important for a quick expansion - as expansion is not fast enough if you just to send a single elite army being backed up by a strong pretender. So there is more choice in the sense "speed" versus "losses".
- it gives melee-pretenders another edge over other pretender designs. Battle pretenders are already powerful and fast initial expansion should not be exclusive to players prefering battle pretender designs.
But that are just my personal thoughts...sorry for that OT-rant...)