Something about this build consist in be always in company. That would change your perception of the Change you are suggesting?
I did already take that into account and the reason symbol DPS is meta now is because you can run zerkas with a ton of heals from Symbols. This build doesn't have that added extra healing from symbols so you will probably need to run more armour to do what you want. But if you're perfect on your dodges and shouts then it may work (and I mean perfect which means, no missing Churning, backstabs, etc)
The second is as a Bunker or Support Guardian, you have to be able to control a point, depending on your team it will be side or mid. Unless you can just kill the enemy bunker (which you won't be able to with this) you have to control them off as much as they control you off, and not having indomitable courage means eventually you won't be able to stop them.