[Maraxus]

Because with some nations with very weak provincial defence you can't really see their strengthes in any other area, maybe.

I think Fomoria tops it:

-The provincial defence can not hit anything, has no protection or defence and a moral so absoluely horrible that it will rout the whole army.
-At the same time, the only good researcher/Ritualist is capital only. (and still no better then average compared with other nations)
-The only good unit is capital only.


And seriously, Banda Log is another good point. The provincial defence is sooo bad, comparing it to a good average is like comparing the sacret units of MA Ulm and MA Vanheim.
Problem is, that a sacret strategy is optional - Provincial defence is something you need no matter what strategy you are going.