If you can lock both diffs at will, from the cab, then it matters a lot less if one wheel of each axle isn't fully loaded against the ground. And physics says that its not usual to have both on one axle off the ground very often, or for very long!
If the approach angle limtation is such a problem, not only would we find there many places we can't go, but syncros would have a much lower reputation as useful practical off-roaders. It ca be a problem, although the front bash-plate and bit of momentum often helps out in high approach angle situations - of course, we're hopefully not talking circus antics here or deliberately chosen artificial situations.
It just so happens that VW based this vehicle on an existing one with a large forward overhang, because that was a good vehicle already in so many respects. It's certainly strong, and doesn't suffer the continual breakages and serious chassis rot that seems a feature of Landie ownership (vintage for vintage)... so VW acknowledged the problem, and with the front bash-plate (skidplate in practice) and the production of the Syncro 16, alleviated it as much as possible. The std syncro with 15" wheels and tall tyres goes nearly as far in garnering ground clearance and approach angle, but not quite. Others have taken this further - i.e. The SyncroMog
And you won't appreciate the advantage of the tight truning circle until you have witnessed it in practice, somethibg else that can be used to avoid the challenge of the approach angle from time to time, as well as get places the Landie can't (or not without a lot of ridiculous shuffling to and fro, digging and damaging the undergrowth!)..
So let's stop theorising till kingdom come, best to come and see for yourself, a picture is worth a thousand words, either it will suit your purposes or it won't, but a lot of hot-air on here will never answer all your questions, whether hypothetical or based on realistic situations. We do challenge them, approach angle incuded, and they usually pull through...
