Or perhaps they were his signings under the usual financial constraints we have all become accustomed to.
I don't think it has a great deal to do with financial constraints. Middlesbrough signed Aden Flint for £7m, he's one of the best centre backs in this division, a notch if not two above Bartley. Dawson's been quoted as being worth £20m+ and he's good, but he's really not much better than Flint.
In this division however you can get away with playing some average players and still go up. Fulham were playing some ordinary players last year and had a threadbare squad. Odoi at centre-back is no better than Bartley and he played an important part in their promotion. For all the hype Sessegnon is not much better than Philips. They also lacked a goalscorer prior to signing Mitrovic in January, yet still finished third in the table. Cairney as their attacking midfielder is not in the same league as Chadli. Macdonald as their 'playmaker' is no better than Morrison.
It's the coaching that elevated Fulham, rather than their personnel. Their goalkeeper would always play a goal-kick to a defenders feet, even when the opposition put three forwards on the 18 yard line. Our players are hoofing it forward even when under no pressure in their own half. It's an archaic style of play that needs to be addressed.