I'm not asking about the definitions of estrange and strange, and I realise that modern usage isn't a strict function of the original meaning of a word. I wish to know why English appropriated both words.
Etymonline doesn't explain this. Its mention of the Modern French « étrange », worsens my confusion, because it insinuates some hidden reason why French only appropriated one Latin word. I read OED but it's too brusque; so I don't quote it.