That said, I'm unclear on the spreadsheet. O'Connor's reported votes have open spots at 2nd team or 3rd team guard.
That's because the sources of these things are podcasts/twitter/articles.
Joe Vardon wrote an article where he specifically said Mitchell/Luka are his 1st team guards, and SGA is his 2nd team, but didn't mention anybody else, so that's why his ballot has so many empty spots.
The ones from podcasts (like O'Conner's), without actually listening, I imagine guys are discussing their votes, and don't realize they've only listed 4 guys instead of 5, or the conversation gets sidetracked, etc. I know on the podcasts I do listen to, this kind of thing happens fairly regularly.
So those are the reasons for incomplete ballots.
Also, Jimmy Butler gets too much love. He had a good season, but I'm not sure that he had an All-NBA season. 64 games played, his team will finish in 8th or miss the playoffs.
The advanced stats really like him.
Top 5ish in things like RAPTOR, PER, VORP, BPM, WS, Player Impact Estimate, with a really good 65% TS%, and solid 23/6/5/2 counting stats. His reputation probably helps too.