I haven't looked up hakol b'yidei shamay chutz m'yiras shamayim in a long time.
Maybe he's showing that it makes sense to ask for someone else to be a yarei shamayim even though you might say it's not bidei shamayim? And since it's bzchus the avos he brings an example (the only one?) from one.
Also I don't know what the difference between chutz and pnimi is.