Can it not do either, depending on how you fit it? There is more than one way to fit a scout suit.

Amarr counter recon light assault

Amarr assassin

The main thing the Amarr scout does better than other scouts is it's passive scan precision. It has the ability to scan at greater precision at medium range than a Gallente logi with an active scanner (non-focussed). It will pick up most scouts further out than any other passive scan, making it a deadly opponent for enemy scouts.

With the exception of a speed hack Min scout, scouts in general are played in roughly the same ways. The various bonuses give them advantages in different areas, but essentially they are all scouts. The Amarr scout is no different. It's precision bonus will just give it an advantage in passive scanning, and a capability to scan scouts beyond what other suits can do. All scouts can be fit as a light assault.

Reasons it is considered underpowered compared to other scouts:

Scan range amps were nerfed hard when the scan falloff was introduced. This was to prevent suits from buffing their hyper precise inner scan rings out too far and turning themselves into walking super radars for their squad.

Unfortunately, this nerf hit Amarr scouts hard, as they were left with little way to buff their diminished medium range scans. This combined with inner scan rings allowing mediums to scan even heavily damped scouts, the massive buff to logi scan range, and the existence of the very powerful Gal logi focussed scans, all diminished the value of the Amarr scout.

The other bonus the Amarr scout has is to stamina. Originally this was the only bonus the suit had. This is not considered terribly good, as the suit already has reasonably good stamina.

Suggestions to improve the situation:

Buff range extenders to 10/15/20%. This moderate buff would improve the Amarr scout's scanning without allowing logi's to become OP at it. If logis remain a concern, perhaps nerf the logi scan range down to be equal with scouts and assaults.

Perhaps swap the stamina bonus for a bonus to biotic modules. This will allow the suit to excel in a variety of ways such as running, jumping and melee. Module bonuses have the advantage of requiring the user to actually equip the right module, rather than just stacking a load of hp.

Maybe look at active scanning. Some proposals have put been forward, such as beam scanning, snapshot scanning, swapping the Gal logi bonus to cooldown rather than precision. I suggest nerfing the focussed scanner range to 50m would be an idea. The impetus for this would be to improve the EWAR situation for medium (and possibly heavy) suits, who currently find it very difficult to avoid Gal logi active scans. The knock-on effect would be that passive scanning would have more of a role.

I suggest trying just the buffs first (20% range amps), and seeing how it goes.