You can use static routes but you cannot use next-hop interface with a multi-point tunnel.
You need to use the next-hop of the specific ip address of the REMOTE side tunnel for each subnet.
Also wondering why you have the tunnel interfaces setup as such a large network using the whole 10.0.0.0/8 for the interface range. This is not a problem, just unusual. But would be a problem if you need to have routing to 10.0.0.0/8 subnets anywhere else on the network that would then overlap with this setup.