Yes, I understand what you mean. I would like to see all 3Pt equipment specify a minimum lift capacity requirement. 2000 lbs at the end of the lift arms and 2000 lbs 4 feet behind the lift arms are two different things. Various tractors I have found lift capacities for, some are surprisingly high, some surprisingly low. I have an old 26 HP, 2350 lb Kubota with a specified lift capacity of 2650 lbs at the end of the lower links.
I have a 7' cultipacker with a straw stitcher. Probably about 1200 lbs.
It would be nice to know what the 630 capacity is.