Interesting point, but the tubes have little to do with the pass band. The IF transformers (the more of em the better) would make the response more "tunnel visioned" (I know, bad analogy) as it would ignore (roll-off) signals outside the passband with more tuned circuits. Gain would be determined by AGC action on most strong signals.
I guess later IF transformers were improved compared to older ones but they would still require some form of stagger tuning and the same bandwidth to pass the required signals.
Interesting discussion
