It can be done (anything can be done!) but there are a few things to be aware of:
You are going to be a slot short - that means you have to sacrifice something when shield tanking a Harbinger. One sacrifice will be capacitor improving modules - and the Harb’s a thirsty bird.
The base shield size of a Harbinger is two-thirds that of a Hurricane, so you are starting from a lower position.
I doubt you’ll be able to fit a shield much more than half the size of a Hurricane.
Minmatar ships are fast, and shield tanking works well with that since speed is also an effective defence. The Harbinger is slow. Most Amarrian ships are slower than their heretical equivalents. That armour fitting tends to slow a ship down isn’t a big deal for a ship that isn’t relying in mobility to survive.
So that’s the negatives. The upside is all the low slots will be free (after the obligatory damage control) - you can put three heat sinks in and tracking enhancers to make medium beam lasers more effective.
You are going to be a flying abomination: a thin tank with a kick like a mule - I’d be curious as to how you get on. I’ve flown Shield Arbitrators because there was shield logistics on the field and it felt very wrong. Slow, massive signature, smaller than normal tank. But it can be done.
If the fleet you are in doesn’t have logistics support, then why is shield being mandated? You’d be much more effective in the fleet with an armour tank, even if they are running shield command bursts, it isn’t going to compensate for your fundamental weaknesses if you shield fit.
I’ve flown a fair range of ships in my time: I’ll agree completely with your view that nothing is as smart as a freshly cleaned Amarrian hull with the sun glinting off it.
I find them much more satisfying to fly as well - they are demanding, but rewarding. You are always working to balance weapons, range, repair and cap, but get it right and it really works.