What is decided per build is the comb's shape - cells to a row, and the rows that follow from it. Its proportions depend on those two counts alone, since scaling the cells scales both sides of the block, so the shape is chosen against a target aspect ratio and the size follows from whichever budget binds.
Details
Choosing by cell size instead - the fewest cells per row that fits a height cap - always lands on the widest, shortest comb that will fit, which reads as a banner rather than as paving.
See also
Other home:
mui_accordion(),
mui_card(),
mui_hero(),
mui_hex_grid(),
mui_home_page(),
mui_list(),
mui_prose(),
mui_showcase()