I suspect that 5w4s will more likely have strong F than will 5w6s, at least as commonly found in nature (no fixed rule).
But one has to remember F can operate towards objects, music, virtually anything, it can be completely detached from humanity.
The way I'd describe myself is having a lot more of the "cordial warmth" than discerning value judgment, and I think that's consistent with having some sp-6 at work (after all, this is more about preventing harm and making self/others feel non-threatened than about seeking deep value in things). My attitude is kind of dry and "just let's find the various angles on things, and try not to get destroyed" and the sole value judgments I seem committed to are moral ones, which are in some sense the most impersonal kind.
4s may in fact lack this cordial warmth, but are much more deeply invested in questions of significance and so on. And 5w4 at least has it as auxiliary.