I started playing guitar around 1986 and bass in 1988 and it was fingerstyle for me for 20 years. Altho' I've been decently proficient on guitar with a pick, the rare times I had to use a pick on bass it felt real clumsy, rhytmically unnatural. SO I played everything fingerstyle, from soul to speed metal (even HC parts, using a really orthopaedic 3 finger technique sometimes). Now, in 2008 I started playing almost exclusively fast HC and demoed a complete LP with a close guitarist friend (who happens to be an outstanding rhythm guitarist from some big metal acts -with a long history of HC-) and by watching him (a guitarist!) I just re-learned to play a bass with a pick. I simply emulated his rhytmical feel. On guitar you can bang it and not get your pick stuck when stroking simply because such soft and thin strings will move away. But on picked bass well, if you hit hard either you break a string or the pick goes flying away. With time I discovered the perfect way to counteract that so that you can play with a guitar'ish feel is to use softer picks, which also provide for some natural compression. For me it's Tortex Triangle .60mm (orange), when NEW. That's the exact stiffnes for me. Probably an hour into a new pick it starts getting softer. I tried Ultex (same gauge) as it's just a tad stiffer, but as so, they crack or even get their corners chopped with my kind of technique. So I stick to .60 Tortex which don't break and are way cheaper so I don't mind discarding them often much.
As you can see in this video my picking pattern doesn't differ from the guitarist (to the left)'s.
As you can also see I use my whole arm, wrist AND fingers to pick, in a typical guitarist kinda' motion. Live I have to mute more just in case my strokes are not that precise, but even with a guitar like arm motion I've grown very precise over these last 9 years. My point is you cannot appropriately do a solid groove only with your fingers, not even with your fingers and wrist, you need your whole extremity for it to flow. I say worry less about picking precision (and the whole pick up/down -púa/contrapúa in spanish- cycle) and focus more about your arm "dancing" around a groove. If you look clumsy or unnatural playing (what I see in MOST picking bassists) it's probably sounding that way too, even if mixed with your band it doesn't show too obviously.
The other thing you probably noticed is groove related, we play strong (down) beats on snares. That for me is ESSENTIAL for modern fast HC, basically not playing the groove as if you were playing some Ska upbeat thing, SO WRONG. Let me show you just a measure to exemplify.
It has a lot to do with the drummer too. Some drummers simply can't give up on the annoying strong kicks on 1 and 3 and the continuity of the hi-hat (measure A), while the good ones (no euphemisms here) do it the other way around. FAST HC IS NOT METAL, it grooves in a very different kind of way, altho' many don't ever get to "click" and play clumsy HC all their lives. I've tried to discuss it in
this totally ignored thread (can live with it, TB is not into pick technique development much). I apply this sort of snare oriented/accented groove concept for many other things I play, not only HC (
an example). It's even made me a better guitarist. Here's a
drums+bass rough take for you to hear how it sounds. And here's the final song it became after some more takes, guitars, singing, editing, mixing, mastering...