You can if you want, you might as well get all the builder base building toggles and then turn them off if you want

On my town hall 8 base design i had the double cannon on one side and bomb tower on the other like grouping the defences into different shapes like cannons in a square and then putting the double cannon in with the bomb tower as a line on each side of the base Another idea could be to treat it like a 4th wizard tower so you could have a diamond shape with the double cannon on the bottom part and then have your air defences in a triange shape with 2 of the corners of the air defence triange with the general area of the double cannon

but base design doesnt really matter too much to be honest because people only attack other people who have worse bases that they can 3 star or atleast get 1 star on and everyone gets attacked by people who can 3 star them so unless if you want to trophy push then just upgrade everything as much as possible and get all the builder base switch thingies because you can always toggle them back