Acidity order of xenon fluorides,oxides and oxofluorides
You have to consider the oxidation state of the xenon.  Higher oxidation state makes the central atom a stronger Lewis acid in general, xenon is just one case.

So we should consider each oxidation state separately.  Look at the ordering when we do that:

+8:  $\ce{XeO2F4}&gt;\ce{XeO3F2}&gt;\ce{XeO4}$

+6:  $\ce{XeF6}&gt;\ce{XeO2F2}&gt;\ce{XeOF4}&gt;\ce{XeO3}$

+4, +3: Only the fluorides are given, no oxygen vs fluorine comparison possible from the list.

The +8 and +6 orderings are consistent with the expected effect of oxygen versus fluorine within a given xenon oxidation state.