You only need a stretch of a F-A to play those chords evenly. It's not that difficult.
First up, it has little to do with difficulty. I has to do with physical possibility! You can either reach a chord, or you cant. Simple as that. Possible / impossible. If it's possible but severely uncomfortable, then I guess you have to use your better judgement.
But also, lets not confuse the problem - the F to Ab stretch is not the really problem for most people, its the inner voices. Playing F - A is VERY different to playing F, C, Eb, Ab!
For me, I can play the F, C, Eb, A chord and I can play the F, C, Ab chord, but not the F, C, Eb, Ab, where the C has to be played by the 3 finger.