Toni,
A finer bit would do a little more.
I used a 1/8 tapered ball nosed mill - I could have gone down as small as 1/32 tapered ball nose.
The radius of the smaller tool can get into the details better.
This is a purchased model, commercially available.
This plaque is the model as purchased.
That being said - there may not have been as much attention to the detail given in the creation of the model.
With modeling software someone could modify the model to add more detail.
That is a skill, just like any skill and needs to be learned and practiced.
I have a Wacom Bamboo tablet and am working on my skills as modeling.
I have a LONG way to go - but I can do some rudimentary things.
As to undercutting - that gets into some advanced 4 and 5 axis machine moves and advanced software.
My machine and my software is not capable of that.
I have seen many people start with a commercial model or rudimentary shapes and finish off with traditional hand carving or sculpting.
I have tried hand carving on the Last Supper, after machine cutting.
I didn't finish that project but I can see that as an optional process.
The possibilities are endless.