I sure hope 15 other GM's feel that way. Barnes' shot can be tweaked and is far from broken. Worst case scenario he's a legit 4-5 position defender who can run an offense. I think he eventually plays most of his minutes at PF anyway. He has a solid push shot/floater and has a nice form on his hook shot. The thing about him that stands out is what you see at about 5:35 in.
That's a full court slam, in control, and 2 steps from the 3 point line to a dunk. If a player can do that and run pick and roll, well, you are looking at similarities to Giannis, Pippen, etc. I'm not sure he is going to be a production wiz like Giannis but he'll impact the game in a bunch of different ways. I think his athletic tools and his foot speed make a gamble on him fizzling out more than worth it.
Garuba is interesting. The only issue is I've seen people say he's similar to that multiple position defender type and offensive players when switched get by him a little too easily IMO. He relies on recover contesting quite a bit and he's not an off the charts shotblocker to make that his calling card.