Cursive Writing

My dear son has taken an interest in cursive writing. It all started with one of the storybooks he read. It had a list written in cursive. So I search the net for a site that has cursive writing and started to print them out for Reese to write. He likes it. He is quite good at it too. So far we did 'a,g,d,c' with just one worksheet for each letter and he is able to remember how to write them correctly. 

I am just wondering, should a child at such a young age practise writing cursive when his manuscript writing is not that good (I do not practise handwriting with him). He tends to mix both upper and lower case together when he writes. He needs more practice. Maybe I should make him practice both. :) 

Cursive 'g' written by Reese

Site that we use for cursive writing:

http://www.kidzone.ws/cursive/index.htm

http://www.handwritingforkids.com/handwrite/cursive.htm