It looks like Fyfe from the suns is the best Floating donut/ capt loophole for D8, Def/ mid classification also. Kosi & Highmore certainly look like the only rookie priced defenders that will play round 1 so depending on your structure, if you need another defender rookie he probably serves that purpose the best.
Alternatively, if you do want a rookie defender that will get games I think Jones from Port is the best bet. Could park him on the bench & hope Ken gives him games early on but the issue there is you may have a situation like many did with Gould last season who sat there all year ... I know a few who had this problem (no I wasn’t one luckily). However, with the sub rule/ longer quarters & less rotations, I can see teams making a few changes every week/ trying to manage their list more than ever before.