Hi Wishface, 
I would definitely incorporate the 3[sup]rd [/sup]finger into your rh technique. 
This is a big deal, considering use of [i]a [/i]is a 33% addition to the rh arsenal, if you like. 
(I’m assuming no pinky.) 
 
My model for rh bass technique was always classical guitar ― thumb, 3 fingers. The absence of tension and a balanced, loose right hand seemed paramount; no picks, no anchored pinky resting (?) on the bass. Not if I wanted to keep gigging into geezerhood. 
 
For straight–ahead thumping, two fingers are adequate; but what if you’re playing modern chamber music, and the score calls for 3 different notes, 3 different attacks/volumes?   
 
Or if it calls for fast triplets (1 note, 1 string)? 
Or a fast 4–note tremolo pattern, where you have to accent the first note of the 4? 
 
What about triplets up or down 3 strings, or arpeggios?   
 
You might try another thing I do ― strike the strings with alternate [i]i [/i]and then  [i]m/a [/i]together. The two together will balance the stronger [i]i[/i] finger. It could serve as an interim technique, until the [i]a[/i] finger could work independently. You might be able to gig this way, if gigs present a problem to the changeover. 
 
Lastly, use it to damp strings – especially the 1[sup]st[/sup] à la Gary Willis. 
 
That’s all!