My opinion:
smaller front sprocket = more direct placement of torque to the rear wheel.
This makes every gear "hit" harder at the rear wheel
That is why in muddy sections you select a higher gear to reduce rear wheel spin.
The 2000 Sherco I used to have, when I got it felt like the gears were a half a selection off, had a "useable" first gear and second was a hillside gear and third was almost unusable. So I went with a smaller front sprocket (needed to use a half link though) This made first a tractor gear that was good for tight flat land sections with many turns, second was good for a bit more open sections and some hills and third was great for the bigger and longer hillclimbs. etc. and with Sherco's 4th and 5th are always trail gears.