The nervous boy who asks to join Harry's compartment on the first train ride was Neville, not Ron. Later Hermione stops by asking "Has anyone here lost a toad?"

Basically, what if Harry's first friend his age was Neville.

Perhaps with a splash of "Hermione sticks around longer because she doesn't feel a need to get back to looking for the lost Toad since in this she had found it and brought it over" thus there is potential for her to stay longer and all three to spend a bit more time getting to know one another