Guest vs. host dedupe

BE2012 SP4 Vray on WS2008 R2.

WS2012 Hyper-V host with WS2012 Hyper-V guests, agent installed in the guests.

Experimenting with deduplication. Using client-side dedupe. Set up a dedupe device and backed up a guest to it, from the guest, a dozen or so times. Got about 6:1 compression. Then changed the backup job so we were backing up the guest from the host to the dedupe device. Got 1.4:1. Added another WS2012 guest, backing up from the host. Compression remained 1.4:1.

Is it expected that dedupe compression will be very low when we back up from the host instead of from the guest?