Just a couple of points to consider here.
1. The NH 1520 is their "economy" model in that size. Might be the upscale model in that size would have better specs.
2. The NH 1520 is a smaller tractor than the 3016 Mahindra. Narrower and shorter - almost a foot shorter - will have an impact on how much you should be hanging off the back. On the plus side, that makes it a more nimble machine.
3. It's sometimes tricky comparing numbers. Mahindra, for example, only quotes FEL strength "at the pivot pins", which is more flattering than other FEL measurements, such as "at bucket center" or other measurements you sometimes see from other manufacturers. Don't know if the 3pt specs are like that because the Mahindra site doesn't say how they are measuring; it just quotes a number.
Not defending the NH or knocking Mahindra here... just saying you need to compare similar equipment as much as possible and make sure the specs you're looking at are indeed the same measurements from one tractor to another.