Tang Li Xue's group met many evil cultivators and robbers on their way, but Xi'er, Yaya, Little Loki, and Lucia could defeat them all with ease.
Nascent Soul Stage masters like Xi'er were already extremely powerful outside the Capital City of the Great Wei Dynasty.
Almost all Nascent Soul Stage masters held high positions in certain factions, so it was unlikely for Tang Li Xue's group to accidentally bump into some random Nascent Soul Stage masters on the way unless they invaded the branch quarters of those factions.
As for Spirit Transformation Realm Grandmasters, they should be one hundred times rarer than Nascent Soul Stage masters. It was probably much easier to find a needle in a haystack than looking for Spirit Transformation Realm Grandmasters outside the Capital City.