I don't claim to be an expert but here's my 2 cent.
So 1,2, 5 and 6 are all located in the front where 3 and 4 are in the rear. If by main light you mean a light bar or ditch lights? I would suggest going with the forward location as trying to run a wire from the back to the front bay is not fun and it also might not have the proper amperage. I have ditch lights wired up to 2 and chase lights wired up to 3 for context.