Funny you say that as I don't have any issues with mine, nor does a mate with his 13.50" wide Boggers on 8" rims, and our land rovers are used regularly off road.
Also whilst out on Sunday we ended up putting two tyres back on rims for a couple of other lads who had 10" rims, I don't think either of them had 12.50 tyres though.
I do think with most things in life, if it looks right, it is right
I'd be interested in reading those threads need4speed if you have any links