I have shore 5*, and baze 4*. Speaking from my experience, I prefer baze over shore.
I run zader(L), Zoba, zarris, tp, baze.
My shard has the typical comps, with some of the better including chaze, wiggs and GK. This is my experience against this team. Vader piles on the dots, and ci converts those dots to hots. But Vader's dots persist and so reappear. Now the target has the same number of dots as hots. My baze inverts his hots into more dots as the buffs and debuffs pile on. Then Zoba nukes the "L" out of 'em. Not sure if this is the best strategy, but it sure is fun to watch.
Now, baze can also aoe dispel. Sometimes I need a dispel to rid of one or more taunts. And baze can pretaunt, negating wiggs completely when I pair my baze with zarris who heals on crit.
Baze allowed my to swap out b2 and Shore, and with the extra spot add zarris.
In the current mechanics of the game, and coupled with my comp, baze is by far superior to shore, hands down.
BTW, not that it matters as it's so easy, I finish arena exactly where I desire to finish. If that's 1st place - no problem. Easily done. I however am smart enough to know arena wins don't mean anything because the 'AI' is SOOOO bad.
If I didn't have baze, I'd be very content with shore, who I've used for months.
These are my experiences, and hopefully helps you think about the possibilities of baze.