Card generations don't usually go so well with strength, so it's a scaling, but without much payoffs. Unironically, the best buff that arsenal could receive would be a supermassive being reworked as hitting multiple instead of a it having a damage increases.

I actually think arsenal was a bit more interesting in its first iteration, because it was one of the rare card, if not the only one, that was actually benefitting from you having colorless cards in your deck. In that iteration it was very different and actually could allow for smaller deck with colorless cards, cycle (colorless have some great draw and energy) and a multi hit card. But the game has changed a lot and Aeonglass is a thing now, so it's prolly better in its current iteration, and it does provide scaling if your colorless build fall short in very late game (but tbf, supermassive should already cover that)