Two wires into one?

have to run two Switch Pro switch panels on my offroad rig. The problem is battery lug space with my winch and everything hooked up I don't have much room to add two more lugs. So my question is can I take the two 8ga wires from the two control boxes and combine them into one 4ga wire?

Might be easier to use a bus for the terminals, or a fuse block for a bit more protection of circuits/devices?

For example - https://www.google.com/imgres?imgurl=https%3A%2F%2Fwww.carbuilder.com%2Fimages%2Fthumbs%2F0020415_busbar-heavy-duty-12v-or-24v.jpeg&imgrefurl=https%3A%2F%2Fwww.carbuilder.com%2Fuk%2Fbusbar-heavy-duty&tbnid=km-gOHxSJDJrNM&vet=10CAcQxiAoAWoXChMI2J_fje7R_AIVAAAAAB0AAAAAEAc..i&docid=4rgRoKw4_migSM&w=400&h=400&itg=1&q=Insulated%20electrical%20bus%20small&client=firefox-b-d&ved=0CAcQxiAoAWoXChMI2J_fje7R_AIVAAAAAB0AAAAAEAc

and something like this for a fused option

https://www.mrpositive.co.nz/6-way-blade-fuse-block-with-screw-terminals?gclid=CjwKCAiAzp6eBhByEiwA_gGq5Pde7SzKkQIopHuebdFt2Y1nUbfkxUR1Cp0EY3W3_WdPgpFzkP7-WRoCgE0QAvD_BwE

There are many different options, if you can check them out at your local auto/electrical store, or your favourite on-line store(s).

Gord I thought about using one of them but space is tight I'll see if I can incorporate them. Do you happen to know of a waterproof busbar? It has 8 outputs you connect to lights and I wanted to make an easy way to connect/disconnect then from the control box, but without the worry of water corroding the screws and eyelets on a typical busbar

I usually install this somewhere convenient and connect my high current circuits to it.

https://allstarperformance.com/junction-block-3-8in-stud-all76146/

There are various marine versions, which may be what you're looking for?

Depending where you are, in addition to the on-line and auto' electrical outlets, you could try a chandler - the place that sells boat and ship equipment?

They can also sell waterproof/resistant electrical connections, if you can't find them elsewhere.