Can I have two routers share the same subnet?

Currently, I have a router on 10.0.0.xxx subnet and the GW is 10.0.0.1 and DHCP range is 50 to 99
I also have a router on a 10.0.1.xxx subnet for another ISP and the GW is 10.0.1.2 and DHCP is 100 to 149
I connect to both for various reasons, and windows has no issues allowing me in both networks at the same time and I can manage both gateways from my browser just fine.

However, I have other devices that I would like seen on both networks.
Currently, one such device is only at 10.0.0.240 and can only be seen on the 10.0.0.xxx subnet.

So, could I move my secondary GW from 10.0.1.2 to 10.0.0.2
The DHCP pools would not overlap (per above).
The device in question could then reside at 10.0.0.240 and appear on either network.

Any see any issues?

Couple of remarks and questions :)

- A router on subnet 10.0.0.0 is insufficient info. Where is this router connected, since a router should have at least 2 interfaces (connected to 2 networks) - give IPs (and network IDs) of both interfaces when describing the subnet please (feel free to leave out any public IPs of course, but still designate them something that we can work with)
- Gateway is also a router, so are these different routers? Are there 4 routers?
- How is your PC connected to these networks? How are the networks connected to each other?
- What kind of device is this 10.0.0.240
- Why the need for exclusive client IDs (50-99 and then 100-149). You can have both at 50-99 and they won't interfere.

Can you perhaps hand draw a picture of the network, routers, your PC, the device, switches, with IPs
Something like Help configuring my home network.

What you want to do may be a simple change or can disrupt both networks. Depends..