Loans are a crucial part of the mix. You should, I say 'should', get players much better than par. We have done very well indeed out of loans for the last three seasons - Sterling, Walsh, Ostigaard, Sam Mac are ordinarily outside our price range.
Just don't be too dependent on them, or else you pay when they leave and the following years' perhaps are not so good. 2 is great, 3 just about ok. In particular they can provide the speed and trickery that is difficult to find in lower divisions - Sterling, Thomas & Giles.
The JCH, Sheaf and James are/were in a slightly different category as they are/were 'loan to buy'.
The ones I am most suspicious of are the loan backs, even though Sam Mac had played well, they can backfire - see Maddison.