Absolutely it is... If you really want to go whole hog on the Word Bearers theme, then may I suggest that you use the Crimson Slaughter codex for your Marine component? Doing so gives you access to Possessed as a Troops option, alongside a slightly altered possessed table that makes them more survivable towards enemy shooting and/or gives them a speed boost to their movement. (and possible Rending
iirc as a possible combat buff!)
The
CS relics also include a suit of 2+ save armour, as well as a special Accursed Crozius for some Dark Apostle love, and the ability to grant a Sorcerer the 'Daemon'
USR which thus allows you the option of fielding a rather formidable Malefic caster.
The only big loss is that outside of the Cult troops, you can't take the Veterans of the Long War upgrade on anyone, which in the long run isn't really a loss at all.