Actually...
My only concern with using a smaller mower (like that 5') behind a bigger tractor is... that in many cases the gearbox on those smaller mowers is only rated to about 45HP. Now... that doesn't mean that you're going to "spin" the gears, but... you may want to be a bit more diligent with checking your mowing area for foreign objects, logs, stumps, etc that can damage the mower.
However... with a tractor that size... a 7' mower would be fine... even an 8' if you're not cutting real heavy stuff.
My only concern with using a smaller mower (like that 5') behind a bigger tractor is... that in many cases the gearbox on those smaller mowers is only rated to about 45HP. Now... that doesn't mean that you're going to "spin" the gears, but... you may want to be a bit more diligent with checking your mowing area for foreign objects, logs, stumps, etc that can damage the mower.
However... with a tractor that size... a 7' mower would be fine... even an 8' if you're not cutting real heavy stuff.