Currently all citizen infantry has the same total resource costs (100), training time (10), and resource gather rates; however, they have different movement speeds, which means faster units (e.g. javelinists) are much more efficient gatherers than slower ones (e.g. pikemen).
This has been pointed out numerous times on the forums, the latest at https://wildfiregames.com/forum/index.php?/topic/26012-task-animations-re-export-and-unit-meshes-fix/page/19/#comments
This patch removes the walking speed differences for all citizen infantry, making them all equally effective gatherers (female citizens, slaves, and healers already have the same speed). This is a gameplay balance change, therefore presumably controversial.