What?
You are making one argument(we can/should play with 2 PGs like Phoenix). You are shown that this argument sucks(they will never go anywhere with those 2 PGs at max deals)! You move the goalposts to accommodate a new version of your argument(Exum is actually 6'6'' and shouldn't be thought of as a PG strictly). By which time your initial argument has absolutely nothing to do with the current one simply because Exum is nothing like any of Phoenix' PGs and you want to use him as something completely different(more like SG who can sometimes play PG/ballhandler). The Phoenix example becomes meaningless and irrelevant if this is your argument.
And if this is it, then we can of course argue how this one works out. I'm much more likely to agree with that argument... but I still like Exum much better as a primary ballhandler in the long-run.