Well the first important thing to understand is we aren't building race cars.
Two, you can open a valve faster and hold it open longer and still gain a little bit of power at the same given timing ABDC.
These motors are old and displacement wise, they are small. To see any real difference you would need to radically straighten out/shorten the intake plenum (the LR design is wack but the longer runners aid in torque production), as well as turn it to higher RPMs. As nether one of these things are doable (fair to say the majority of the LR crowd wouldn't take the time or spend the money to go that route), and tuning the ECM is such a headache; we have to pick from cams (very few) which will work with the hardware we have to run and that don't produce crappy results in a untuned form. Plus I feel like D2s are pretty close to their MBT in stock form anyways. I personally wouldn't add any timing if I was tuning it myself. I would simply tweak the VE and fuel tables to where they were good and leave it at that. Again, not building race cars, so I wouldn't worry about those last few horsepower. Especially on a frail fragile set up like the one we are talking about.
Thus we have like 3 profiles to choose from, all of which are pretty close in specs, and lobes are pretty mild (compared to some of the other stuff I see). I mean IT IS an old as flat tappet motor, that you can't adjust the timing, VE, or fuel tables to make it take advantage of better springs, longer duration, and higher RPM ceiling. So for us EFI guys whom are bound with those parameters yet want to run a cam that is a little better than stock we have a couple choices. Could the engine be optimized more? Of course it could have, but we would have to loose a lot of things in the process or ship our ECU overseas to get a map flashed in. Trust me, you wouldn't want a bench tune for an aftermarket cam anyways, not without being able to email the tuner datalogs before hand. Then you might be okay. An important thing to remember is that OEM cams are designed with a lot of other things in mind, such as valvetrain noise, valvespring life, lobe wear, ect. Taking that into acount it is easy to see how one of two cams very very similar in specs might still make a better driving vehicle without any additional changes outside what two crappy narrow bands can do.
I bought mine mainly because I thought it would last longer than another stock one, plus it was cheaper. Which I would dare to say is usually the case with everyone else that changes cams. "Hey I'm rebuilding the motor, why spend $20,000 on a Land Rover cam when a Crower one is $150? Plus it makes more power too man!" *chug beer, high five*.