1st x pups can come in all shapes and sizes,I once bred a litter of 1st cross wheaten/greyhounds from a greyhound dam,some pups where short and very wheaten looking and some made over 25 ,26 " but they all had rough wheaten coloured coat,,,
and like Bird has said most 1st xs are bred from greyhound dams because they are easily got,
not many farmers are gona let you mate a greyhound to their working collie bitch .