You are only missing that the coats were not quite the same, and nor were the boots.
So they 'could be used to represent Légère regiments' depending on whether or not it bothers you that they are not exactly right. It's similar to using Austrian figures for Hungarian regiments: not exactly right, but very hard to see that it's not exactly right with the right paint.
Hat does offer five boxes of 28mm French light infantry, but they are a little smaller, measuring about 26mm from foot to eye level.