I'm not sure about long - we have rehearsed this one many times but for my money, if one cannot be sure of a one shot kill one has no business engaging a target at that range. 3-350 is a long way to shoot at a deer, becuase one should get closer in most cases. But, sometimes because of gusting wind etc, 200 is a long shot.
As for short. Well you know the round is below the sight line up to 25, so one can learn to shoot a touch low between 25 and say 100 on the small deer.
Generally speaking, if one wants a decent carcass one is going to do it with one round, and one will be shooting at a deer which does not know you are there or is still reacting. In which case, one size fits all. The 270 is a bit big for the (very) small deer, but for roe and anything bigger, woods, open fields, stubbles who cares. The 270 was just fine, I thought.
I don't I'm afriad subscribe to the many guns arguemnt. Get good with one - hopefully very good. Pays in terms of returns I reckon. Having said that, because of the small deer problem of which we shot many, one needed a smaller calibre, hence the 6.5. but the 2 rifles were identical Tikka m695s. So one wouldn't have known of any differnce other than by looking at the cartridge. Even the triggers were carefully matched.
Perhaps there is pleasure in owning a lot of guns, but in terms of killing deer and vermin, effectivley, I'm sure the best answer is to stick with one. I did have a third rifle - for clients and for foxing. M695Tikka 270! different one which wasn't my nice one, and I didn't mind putting 90g hollow points at full bore through it for foxes, which i wouldn't have dreamed of doing with the good one.