I'm interested where those statistics come from. Looking at Transfermarkt, the top seven clubs loaned 63 players last season, including 42 from PL/EFL clubs. That's an average of 9 players per club in the top 7 positions, 6 of which were from the PL/EFL.
The other 16 clubs in the National League loaned 121 players in total (7.56 per club), of which 91 were from PL/EFL clubs (5.69 per club), which aren't too different to those in the top 7.
All clubs bring in loan players, to a greater or lesser extent, so bringing in loan players in itself doesn't suggest that a club will be successful. Sutton, the champions, and Dover, who were bottom, both brought in 5 loan players apiece (albeit Dover's were in a truncated season).
Barnet (9), King's Lynn Town (7), Woking (19), Wealdstone (13) towards the bottom of the table brought in more than Sutton (indeed Woking (20th) and Wealdstone (19th) brought in more than any other club, including those in the play-offs).
I don't think number of loans tell the story: it's more the number of appearances by loanees.
I'd expect the successful clubs had fewer loans but those loans contributed more appearances each. Having 10 loanees who made 1 appearance each would have less impact than 5 loanees who played 40 times each.