This is in no way too small for outlining, it just needs a softer touch.
Some thoughts on where you might next take the design, and an edit:

-Added a backpack because it makes the guy feel more like an adventurer, he's going somewhere.
-Straightened the cane. Without a shitload of antialiasing I don't think the angle will cooperate at an angle.
-lightened the sleeve, indicating that he's wearing a waistcoat
-added a patch to the knee
-cleaned pants
-fiddled with colours
-lit the face to indicate where the masses are.
-added a hint of backlight to the hat but didn't light the front; not sure what to do with that actually.
issues with the edit
-bottom of the sleeve is now banded
-legs kind of nobbly
-blue still needs tweaking.
-face lighting still needs more contrast.
It could still use a lot of work but it should give you some idea of my thoughts on the matter..
Click the image to zoom in to get some idea of where I was going with the edit.
Hope this helps!