Well blitz, considering the germanics were praised during the ancient times as the most loyal warriors of western and middle europe (we talk about the absolute elite here) i think the bodyguards should have a edge over their celtic counterparts, but i think the team will make the right decission.
But i think it shouldn't be forgotten, that the romans hired not celtic or other nation's elite warriors but germanic ones for the personal protection of their leaders, so i think with this honor code, as you call it, they should have higher morale stats. As we can't display the "loyality" in EB it should perhaps be displayed in Morale.

I also suggest to give them the throwing spear as secondary weapon, after all the exceptional warriors of germanic tribes were known for their ability to throw their frame a very long distance...
Good idea here, i though of the Herthoz(as i called them during planning phase) those long months ago in this manner(throwing spear, long range, very high morale, and sword).

If you think there are too many sword units(still hoping you've got rid of the axe idea for the wolf-warriors), scrap the "normal germanic sword unit(not the cherusic one) Sorry, just can't find the name you've given them. Just a idea.

Take care.