Everyone believed that russia was going to throw human waves at defenders - it is what they have always done. I have no idea where you get this idea nobody thought they would do it.
The only difference is that only you think it would actually work. Modern technology has rendered it obsolete. As the results at Vuhledar and Avdiikva have shown.
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Similar size, if at full strength. But none of these are going to be at full strength.