Not necessarily; for any pedigree sheep you need to check for basics like correct mouth, correct pasterns, no inheritable conditions like entropion, hernias (they are more in cattle than sheep), mother has enough milk/no bad maternal traits. Then once they’ve met that basic criteria you can look at breed standard. I normally kick out at least 10% of my ewe lambs and kill them, and out of the remaining ones, will put some to a terminal ram- they haven’t met my expectations between weaning and tupping as shearlings but they are fine for rearing meat lambs. I don’t keep any lambs from ewes in my B terminal flock.
I don’t think ryelands are quite as prolific as what you’ve been told. I’d expect about 160% from them.