Defensive Roublade? Is that a thing?

Your idea works but most who use armor teams would agree that ward is the preferred armor buff to run, forgoing hone/fortify because they are harder to use and less reliable. This kind of setup makes owl tomes stronger because your unit should take next to no damage from non-special attacks, while getting a small attack buff and doubling in return. This normally won't give you the kind of firepower to take out triangle disadvantage, the way blade tomes can, but if you're running an armor team then you probably have a capable green.

It will work but I'm not it's strong enough with all the Panic Ploys running around. Armors like the Goad/Ward better imo, it can really be stronger.
And this set might also be overkill, since she doubles back anyway, she'll probably don't need the extra firepower.