They aren't as heavy as you might think.

For Pottinger, lowest weight is no conditioner, highest is roller conditioner, flair conditioner is slightly less than roller.

351: 2200-2900lb

X8: 3900-5300lb

V10: 5000-6400lb

S12: 4500lb (no conditioner option).


For comparison, a 946 Moco JD pull type (13') weighs up to 7,100lbs 


If you get through the grass with your self propelled discbine you will get through those areas with a triple mower.  Even if you stay with 480s or 520s, you still have a much bigger contact area than a self propelled mower does.  Go to bigger tires and you will be even more happy.  I'm sure you have at least one tractor that does not need to fit between rows correct? Make that your mower tractor with big tires.