On the individual monster pages, the Alphabet Giant has the highest defense in the zone at 131 (141 * 0.9, rounded up apparently). Add 10 to that (I'm sure a post by RT could be found with that number) gives 141; mafia could be rounding down the multiplication result or something to get 140 instead of 141, but since that linear hit-chance formula is only an approximation anyway I doubt the difference of 1 is at all meaningful.
Regardless, the problem is with the wiki, not with mafia.