Are filler middle names less common for boys?

Based on posts here, and people I know who've named their babies, filler middle names are still pretty common for girls. The Janes, Louises and Maries have become Roses, Graces and Mays, placed in the middle for the purpose of achieving desired flow (not that everyone who uses these names does it only for the flow, but plenty do).

However, the only boys name I know used in that way is James. What has everyone's experiences been? Do people care less about the flow of a name for boys? Or are there equivalents I haven't heard of?