First of all, Tomcat 4.1 hasn't been supported for over 4 years.
Second, you haven't read the page correctly. Look at the end of the "Class Loader Definitions" section where the search order is explicitly described.
If you want to change the delegation order then look at the delegate
attribute of the Loader element. This is supported in all Tomcat versions from 4.1.x to 8.0.x.