I made exactly that some time ago and I can tell you it is probably the most “noob”-friendly build you can make. Reason for that is simple: unlike the now “classic” reflect/retaliation warden build, it does not force you to stack reflect or make substantial changes to your gear in order to deal with ranged mobs.
However, I got rid of the acid retaliation damage because that is supported only by the Absolution set. In order to reliably debuff acid/poison you have to invest in vulnerability and those points are better invested in Overguard. A pure physical/internal trauma + pierce retaliation build will yield better results on ultimate. One of the main reasons for that is that ultimate mobs do not resist physical damage while ch’thonian enemies are enormously weak to pierce (this is a less known fact but you can abuse it easily with the Final Stop shield).