Here is a close up shot of the Red units. The blue units are identical only blue.
There is no unit for light infantry or grenadiers in The Portable Wargame. Dragoons fight like other light cavalry.
Light Infantry: SP 3, Range 2, -1 in close combat in the open, Must take the retreat option if available when fighting close combat in the open.
Grenadiers: Behaves like other Infantry units for movement and shooting. Close combat at +1.
Cavalry get a +1 to hit in close combat.
I seem to be tweaking this game a lot. The best part is that it is pretty hard to break when modifying the rules.