If MMC are to source engines from a single vendor, it strikes me that they will have a number of criteria:

1) Wide range of engines from 100 ish to 400 ish bhp
2) Design and engineering support readily accessible (therefore European)
3) Already invested successfully in hybrid and electric power trains
4) Access to rear wheel drive transmission systems
5) Single set of vehicle control systems
6) Aligned brand values with MMC

I will have missed a few that other more knowledgeable folks can add.

A list like this does not have many contenders - BMW are probably the only fit.
JLR have yet to market a pure electric.
VAG a possible but no RWD
GM - all RWD is in Australia or in pick-up trucks


Paul
Costock, UK
Plus Four 75th - Furka Rouge - Pip
Disco 5
Teddy - 17h1 Irish Draught cross