You’re always going to have misses in the recruiting/transfer game (Fred had SDW, Sledge, Bluford, and so on). The guys I listed should’ve been a good enough foundation, but it was when they left early or didn’t pan out that Steve didn’t seem to have a backup plan.
I'd also argue that he struggled to properly use the quality guys he was able to recruit while they were here. Of your list, I think you could easily say Wiggy, THT, Lard and Bolton were misused at times.