replaced the 18" wheels and tires on their newer 2500 truck with 16" to get away from height and fifth wheel clearance issues. Don't know why the new trucks are so tall but my newer (2015) is 58" tal...
I’ll say no to the 16” wheelz due to brake clearance, but check. May work on fords since your 2015 is same chassis as a 99 that did come with 16s....I think. Otherwise get the smallest load rated 18s you can and reverse level the truck if you can or need to. But make sure you’re accounting for suspension squish etc.