SAIC's plans for the UK market are bizarre at the least, as you've mentioned, rapid expansion of the UK dealer network for just two models for the next couple of years at least..?
Unless, of course, SAIC have bigger plans that we don't know about, e.g a full model line up, which seems highly unlikely. Perhaps the roewe vision concept is destined to also be an MG. Along with new 3, ZS crossover and larger crossover. All speculation, but perhaps they wanted to stop assembly at Longbridge now, before new models are introduced, probably to save costs on lease and retooling the lines.