[Edi]

That depends on the site frequency used and the types of provinces you have. Searching farms with the pretender isn't too good, swamps, forests and mountains are a better idea. But I'd rather use him for research and lesser mages burning gems on radar spells like haruspex, augury etc to find sites. If you use a high site frequency, the pretender may be justified going out every now and then but generally that kind of magic stays home at work instead of spending half the time twiddling his thumbs (moving from place to place).

Edi