The others are giving you good advice... Sometimes.. even if a tractor 'will do it'.. 'it shouldn't be doing it'.
Weight is as much an issue as hp... You don't want a 'wag the dog' scenerio. Also. "single use' vs 'constant' use is a factor.
If i had a 16xx and had use of a 5' hog, to use once.. to knock my weeds down, then I was purchasing/switching to say a 4' for maintenance use .. then, i fthe tractor handled it ok.. I'd use it.. as long as it didn't lug ( lug= giving it more throttle with no more rpms being generated ).
I wouldn't have considerd a 5' ruff cut mower for my 1700 for the same reasons ( though a 5' finish mower.. perhaps.. of course.. I have nothing that a 5' finish mower would be any good on.. )
Soundguy