No, you miss the point.
If LMCE doesn't know about the tuner cards, it not only can't set them up in the setup wizard automatically, you can't use them to control legacy A/V devices...
You'll need a little bit of shell scripting experience to make the plug and play scripts.
If you look in the web admin, Advanced > configuration > device templates, you'll see the main UI for manipulating and creating templates...
Select the PVR-150 template, and have a look. You'll see references to various .sh scripts, these can be found in /usr/pluto/bin
Basically the template specifies what the device is, what it can do, and how it should set itself up.
The shell scripts are the needed steps required to set up the device itself.
Basically, any device that LinuxMCE can use effectively, needs to be able to output MPEG-2 to something like /dev/video0, like the PVR 150/250/500/USB2/etc do.
I can be here to answer questions.
-Thom