The built quality also matters. Equal tension and so.
Forget about upgrading spokes on your current wheels, 16/24 is just crazy. Don't throw good money after bad money.
32 spoke wheels should be fine and has many economic hub and rim options. Use double butted 14/15 brand name spokes and brass nipples.
There are probably good reasons to have 4 fewer spokes in front, but what is the point? To save 20g? The frontwheel also takes all brake forces.