Well I for one think you should carry as complete a tool set as you can.
At minimum you should have enough tools to work on every system including wheels axles and suspension. And with doubles of some tools to use as Backing.
The small difference in weight to your Pick Up is negligible. As a sailor I like to be prepared to fix whatever may go wrong myself. And I think that philosophy is a good one for RV's.
Too many complain about the high price of repairs and shoddy workmanship but they don't become self sufficient in terms of being able to repair their own units.