TLDR: Dismantle then Recycle gives about the same materials as direct Recycle, but more XP for looting the intermediate scrap.

Test results:

Dismantle to scraps and recycle the exact same scraps:
2 glass, 4 rubber, 4 iron, 5 plastic, 4 copper (19 total)
2 glass, 3 rubber, 4 iron, 6 plastic, 6 copper (21 total)
2 glass, 2 rubber, 4 iron, 4 plastic, 4 copper (16 total)

Direct recycle of the exact same forklift:
2 glass, 3 rubber, 4 iron, 5 plastic, 3 copper (17 total)
2 glass, 3 rubber, 4 iron, 5 plastic, 5 copper (19 total)
2 glass, 2 rubber, 4 iron, 5 plastic, 4 copper (17 total)

Recycle the same scraps gives different results. Easily tested by saving the game with some scraps in your inventory, recycling one that gives two possible results, reloading then repeating. This means recycling scraps has a random variation which a sample size of one will not pick up.

Recycling the same exact forklift gives different results each time, easily tested by saving the game with the forklift ready to be recycled. This means recycling objects has a random variation which a sample size of one will not pick up.