It could be that. The smaller type are usually better sheep that have reared as ewe lambs while the bigger ones have been run dry and got too big. They are mostly a different smaller type too not just stunted because they havent grown.May be wrong but it sounds like an issue when the lambs are growing/developing which is then showing up once they are ewes
I think like most things its more complicated than just onw thing being wrong. Its most likely a mix of fine boned ewes, less feeding cake, low calcium soils and 2 lambs pulling off them all adding up to calcium deficient ewes that lose their teeth. Needs sorting whatever itbis inhad to cull 1/3 of my twin rearing ewes last year