Combo Racks?

So I haven't been able to find an awsner for my question (maybe I'm just not looking hars enough?). In Combo racks they typically hold small tubs and larger tubs lengthwise. For example 4 6qts on a shelf or one 41q. How would you heat that? Belly heat across the shelf works for the 6qts but then the hotspot runs all the way down the 41qt. Is that okay or would it need to be wired differently?

You can heat everything up with a piece of 3 inches or 4 inches wide of heat tape. Heat tape is usually in the back of the tubs. and a 41 quarts tub does not need a bigger hot spot than that.