Question about IPv6 Subnetting and eui-64

Hi all,

I know the sidebar says not to ask how to subnet and i'm not. I know how to subnet both ipv4 and v6, however i'm a bit confused about how eui-64 comes into play....

So i have a prefix with a subnet ID: 2001:1b70:82c8:e001::/64

And for the purposes of a lab id like to have 10 (so 16) subnetworks of this prefix for use as 2 access layer subnets and 8 core uplinks between routers.

so i take the the /64 and create 16 /68s but from my understanding in order to make eui-64 work you can't do this. (eui-64 require the full 64 bit interface id

So i figured i would just leave them as one big /64 but i can't do this because a router in a subnet boundary and configuring ipv6 address 2001:1b70:82c8:e001::/64 eui-64 on multiple interfaces on one router causes an overlap error.

Essentially what i want is to configure 4 routers to use the above prefix and eui64 on 3 interfaces each so that they can talk to each other using their global unicast addresses and static routes.

I don't know how to get the global unicast addresses to be a part of the same subnet on a 2 host link without overlapping with other interfaces or wasting 65k addresses on a 2 host link by simply changing the subnet bits

here is an image of my topology: Topology

please help