I think the Aussie army and Land Rover got it right with the Perentie.
Galvanised, simple to work on chassis;
Proven, reliable Isuzu turbo diesel (3.9L);
Wider cab/bulkhead, all galvanised which would allow the 'defender elbow' issue to be sorted if kept as a 2 seater cab.
Minimum electronics (electrics are all pretty much field servicable, electronics arent!)
Not sure what they did with axles but the more recent range rover P38/disco 2 axles are pretty good in standard form.
The Perentie's have survived 20yrs abuse in the aussie military and they are having them refurbished to last another 20 as they can't find a cost effective replacement so something must have been right.
I have first hand experience of the investment TATA are putting into their engineering, foundries, facilities etc.
Land Rover has for the last 10yrs min. just bought in most components. the engineering departments had to get those components to work together, they never designed them, nor did they invest in anything more than assembly plants.
I can see TATA keeping the defender as ongoing development and may bring it back to its former glories as the working 4x4 of choice.