Sounds like they need a few traffic wardens with webcams on their helmets, and a few deterent punitive sentences/fines to prevent people "dumping stuff".
Go back to "if guidance not on" P1 takes responsibility and uses 4 eyeballs. Time and motion needed to see why TRMs not in right place at right time. Can't anyone else be trained to turn on guidance and drive airbridge, or indeed why not activate both from flight deck like I do with my garage door?
No doubt there will be numerous reasons why none of the above are feasible!
From a simple surgeon and FI/FE