Just read in a magazine (didn't pay attention on the net) that the Orion spacecraft service module will not slow down the CEV-LSAM stack into Moon orbit (like the Apollo SM did) but it will be the LSAM's job to do that!!!

That's why the SM is so small!! Perhaps for LEO use, no more is needed.

This means the Orion-LSAM will have to be piloted from the LSAM before they arrive in moon orbit. This also means the Orion spacecraft cannot be tested around the Moon without the LSAM.
And it means the Orion SM will perhaps only work twice with weeks of mission in between (first to rendez-vous in LEO with the LSAM and then for TEI).
Perhaps it's a good tactic.