DON - Yep, I get scratches on my concrete drive, but what you gonna do? They wear away and fade eventually. On sealed blacktop you would have to re-seal it.
CHARLIE - My little old letter-series FARMALL's only have about as much HP as the new lawn tractors sold @ Home Depot, they just weight TEN times as much.
SON & I put 900# of weight on the back of the '51 M and to be honest, without chains it didn't make a darn bit of difference. I don't think 2000# would make it's rubber tires grip concrete. SON & I moved snow two years ago on Christmas day before we had Christmas dinner. The M wouldn't move ANYTHING on concrete. It would move a little snow on the grass until it spun a tire and then it was helpless on the bare frozen dirt.
Both sets of chains for the big tractors are 2-link chains, in fact, ALL my chains are 2-link, the ones for the 6-12 turfs on the 70 & the 23-8.50 'Stones on the 72. they still have cross chains over the lugs and they do grip really well where they cross, LOTS of surface pressure, but they do wear the chains faster, especially if they spin a bit. With the cost of chains, I think that alone is worth putting chains on turf's instead of lugged tires.
Last summer I did a LOT of heavy grading with the 70 & belly blade. I had chains on the 6-12 GY turfs all summer. I tried just the plain turf tires and it was worthless, put the chains on and I could move some dirt.
I think if you were on loose crushed rock, if there IS such a thing in winter with snow with tire tracks in it, a lugged tire would be better than a turf tire, the lugs could get a bite on the rock, but chains on either tire would still grip MUCH better.
If I could find a set of almost BALD tires for either big tractor, something already on rims and/or wheels, I'd try chains on a smooth tire for a winter.