Arjay,
Webmin and SME work in fundamentally different ways, which just can't be reconciled. Webmin modifies the config files (/etc/...) directly, whereas SME compiles the config files from the templates and e-smith specific files (/home/e-smith/*). This means that any change made by webmin will be thrown away next time SME recompiles the config files.
This might look silly at first sight, but the templating system in fact makes it much easier to upgrade the server without losing an existing configuration. For example, a security upgrade requires a change to smb.conf. With webmin you would have to add the new parameters manually. With SME you get the update in the form of a template which you recompile with expand-template and all the old and new settings are nicely merged into the new smb.conf. This can be done with an rpm, so no knowledge what so ever is required.
If you don't like the look & feel of the server-manager, you can easily adapt it to your own tastes. Half a day to understand the concepts behind server-manager and to customize it would get you a long way.
Michiel