Yes, you can do that. The only problem will be that the analog receiver won't be able to control polarity on the voltage-switched LNBFs. You'll only get horizontal transponders, I believe. This is why most of us slave the analog receiver behind the digital receiver. The digital receiver, in this case, will control polarity, and the analog (connected to the loop-through IF output) will see whatever polarity the digital is on.
Also, keep in mind that if you are using an analog receiver, be sure to use a STANDARD (L.O. 10750) LNBF.