Heat tape questions for rack.

I am planning a small closed rack with belly heat. I would like to try breeding to see if we enjoy it as a family.

I want 4-5 41qt tubs sideways and I also want 8 6qt (2 rows of 4) tubs standard configuration.

I plan in using hides for juvies in larger tubs or I will use 28qt as they grow but the shelf will take up 41qt so it will be more flexible.

My 41 qt shelves will have heat tape on one side and the 6qt rows will have the heat along the back.

Originally I was going to use 11-12" heat tape but that wouldn't allow the hatchling tubs. So my question is this: Can I use two rows of 6" tape on the big tubs and one row on small tubs? Every section will be cut exactly the same size so I can have it all on one tstat.