A major part of the MEIR is asymmetric approaches. To do a load of training on single-engine aircraft (whether sim or not), and not be able to practice such a major part - and one which a lot of people struggle with, too - is madness.
As for not having a sim, it would definitely be a big drawback, but not impossible. The biggest issue would be the extra cost - but other advantages of sims are that there's no difficulty booking approaches at busy airports, the weather can be as good or as bad as you want depending on your stage of training, ATC can be as helpful or unhelpful as you want depending on your stage of training, you can be re-positioned at the start of an approach without having to fly there first (which can double the number of approaches you can fly in a given time when you are at the early stage of learning to fly approaches), the instructor can fail things when he wants including things which would be dangerous in the aircraft (engine failure immediately before or immediately after take-off, for example).... the list goes on.
But none of these can't be overcome - there are very few schools which offer training for an IMC rating which have a sim, for example, but the advantages of having a sim for this course would be identical to an IR (except maybe the cost difference would be less), which is proof that it could be done.
FFF
------------------