JSF view templates are 2-dimensional templates, and the concept of time (and therefore rendering order) doesn't apply to something purely geometric. What you're really interested in is the sequence of processing for AJAX.
I'm not sure how to do that in vanilla JSF2. RichFaces has a special AJAX status tag that can be used to display things like a "please wait...". I use it extensively, in fact.
An IDE is no substitute for an Intelligent Developer.
Thanks Tim. I've insisted to my developer to use another method of rendering the second component by adding extra flag bean, based on flag value second component will be rendered. The whole intention was to load the second component after first since, based on first second would not be needed.