I’m my opinion the shorty is better in mud than the Mary but the Mary is a better all rounder if it dries out.
This, but theres not alot in it.
Personally I find both decent in the blown out, loose, dusty carnage of a dry summer too, but I’d give the edge to the Shorty in those conditions.
The Mary is better on hardpack and at trail centres though, although the shorty gives a better account of itself than it should given its tread.
I suppose if you have thin soils and lots of rock based strata, and mineral soil, an Assegai would do ok, but tbh, I didn’t like it in the dry anyway.
For the OP, I think either will do, But it sounds like the Mary would be the better choice if winter is more trail centres than off-piste.