It was made clear to me that when using the ablative of manner with a noun defined by an adjective, the adjective can come before the preposition if the preposition is monosyllabic. A well-known example of this is of course magna cum laude. I also know that 'cum' can be omitted altogether.
But what I'm curious about, since I'm not well read in Latin, is whether this same rule might apply in other uses of the ablative. I've seen the expression "tantum alto in monte relictis" (again, I don't really know enough Latin to determine whether that's enough to make sense of what that means, so pardon my ignorance), and it seems tantum can't be defined by 'in', and relictis throws me off, since I'm not able to be entirely sure of its meaning. Is it some kind of declension of the perfect passive participle of relinquo?
But most importantly, 'alto' is in the ablative, so it seems like it can't mean "high in the mountain," but must mean "in the high mountain," which would suggest the same rule as in the ablative of means.
Put simply, my question is to what extent does the rule go? In how many cases, how many examples, can the adjective precede the preposition? Would magna in nave mean "in the large ship"? Would lato ab agro mean "from the wide field"? Furthermore, would pulchrum ad oppidum means "to the beautiful town"? I'm sceptical, but I do need this made clear for me.
Thank you VERY much in advance for any help I receive.