Hi,
I doubt that you would be using any tunnel interface in policy based VPN, if yes then use another tunnel interface in route based VPN. You can use same tunnel interface but btter to use another one.
It's very common scenario where one VPN device can use same IP/interface to form VPN with multiple different IPs/Gatways/VPN peers.
Please let me know why do you think it will not work and will see if that can cause issue.
Thanks,
Vikas