If you are sure about what you do, why not indeed.
But remember that the current simple-methods.xsd must miss the elements which were initially provided by the simple-methods-v2.xsd in the CompoundWidgetFiles.patch from 03/Jan/11 02:27. I try to find them but gave up. I think It should not be that hard to find and put them in our current simple-methods.xsd, but I did not :/.
Regarding splitting patches it's easier, for me at least, to have only 1 patch. Or if it's really hard to review several smaller patches in only one Jira issue. This at least if it makes sense from a functional perspective. Else better to create several Jira issues (seems not the case here).
It's fun to notice that by splitting issues and patches we would work contrary to what the compound screen feature try to avoid (opening, searcing in more files, etc.)
And last but not least, Adrian said that, even with his complete changes, the Eclipse auto-completion feature was not working properly. So It's interesting but I feel there are more work in your plate that maybe you envision
Thanks to try anyway!