The issue with doing it this way is thers’ll always be a massive list of ‘misses’ for any club, players that arrive on loan or a free transfer and then leave. There’s normally two or three every season for most teams, but the hits arrive once and stay for a very long time so the numbers always look skewed.
I tend to just phase out any squad/emergency loans, backup keepers, cheap young prospects on trial etc. and instead just focus on where a manager spends actual money.
Heitinga was player of the season for us so why is he in the miss column? A very good player who covered Jagielka and Distin excellently, thrived when he started at Cb, and covered CM and RB adequately. Jelavic wasn’t a miss for Moyes, he was phased out unnecessarily early by Martinez when he could have been used as a backup for Lukaku a lot more.
I’d say his significant bad buys were Kroldrup, Van Der Meyde, Simon Davies, and Beattie, maybe Bilyaletdinov at a push although I always thought we didn’t use him correctly. Even then though in comparison to what the rest of the PL were spending these weren’t even big fees. Maybe only Kroldrup’s was at the time for a CB.
Yakubu, Mirallas, Fellaini walk into this current team. One snapped his cruciate and still then bagged 17 at Blackburn. Mirallas was a key player for us under Martinez. Fellaini was sold to United for close to 30 mill and was still a key player for them under numerous managers. I wouldn’t put any of them down as misses.