I would not recommend that for multiple reasons, like user experience, service availability, cost, and others.
Call coverage is important yes but what you want to setup goes south as soon you think on a third call. What if the two phones are actually on a call and you have a third, where are you going to send it? No Answer doesn't work on that case.
Adding multiple lines with the same members will only extend the hunting period but at some point it will exhaust all available options.
I don't know the user case but it will be better if you handle the call somehow like sending it to VM or a recording like "sorry try again later" or anything... leaving the call there endlessly sound troublesome for me, what if it is a ghost call at night?
Answering your question, the best way I can think of, will be having two Hunt Pilots and make them to RING each other for the No-Answer condition.
Call -> Hunt A ---(no answer)---> Hunt B ---(no answer)---> Hunt A ---(no answer)---> Hunt B........