Battery placement and drilling question - 94 bass boat

Hi,
I have a '94 challenger bass boat that I am re-writing as it was an absolute wreck when I bought it. There are two deep cycle batteries for the trolling motor and I switched the third out (engine + electronics) with a lithium I had from my kayak.

Do the batteries weigh enough that I can't move the two heavy trolling motor batteries to one side and have the lithium in the middle? I am not sure how sensitive bass boats are to weight balance.

Also there are two "tubs" on each side, the old charger was bolted to the tub on the left and I wanted to make sure I can continue to do this. They seem hollow but holes in boats sound like a bad idea even though this should be fine, I wanted to confirm.

Side note: I am replacing the fuel line, adding a master shut off, and adding a fuel/water separator, trying to make room so it doesn't go over electronics.

Thanks!

I don't see why the batteries would affect balance that much. You weigh more than those, and your weight is all the way to one side while driving.

If I understand you correctly, the tubs you're talking about are like boxes glassed to the sides? Those are just full of flotation foam. You're fine to attach stuff to those, just put a dab of silicone over the hole before you screw into it to seal it.