I get it. I remember watching Barnes' FSU tape before the draft and coming away feeling like he could be Kawhi with a better offensive game. His defensive versatility and awareness for someone that young was extremely impressive. Was an elite facilitator for his size. He was kind of similar to Mobley in that he looked like someone still growing into his body, and that once he got stronger and learned how to harness his athleticism his game can go to a totally different place. You could tell he wasn't all that comfortable shooting the ball, but his shot wasn't broken. His raw numbers didn't look as good as the other players simply because he didn't play the same number of minutes as Cunningham, Suggs, Mobley, etc.
I thought they could both be 1st team defense / DPOY candidates on a regular basis. I would assume that if the players were flipped we'd feel the exact same way we feel about Barnes as most Cavs fans currently do about Mobley.
Mobley probably has a slightly higher ceiling simply due to his size, but Barnes has all the physical tools and ability to develop into an MVP caliber player as well. As much as I like Mobley, at this point I can't definitely say that Lauri / Mobley / Allen is a better front court than Barnes / Lauri / Allen. The Garland/Barnes/Lauri/Love/Allen lineup would've been a nightmare to try and defend.
I'm thrilled with Mobley, but both buys still have loads of untapped potential. It's going to be a while before we have any idea who the better player actually is, and it's possible both guys reach their peak and there's still not a clear answer to who is better.