Arbeia/Tinamutha (?)

I've got myself into a bit of a muddle, a plot hole involving time and geography: I need to get a warband from Galloway to Bebbanburg lickety-split. If they were only a few people, I'd put them on a boat to Solway Firth, then send them galloping along the Roman road to Arbeia-that-was, then taking ship up the coast to Bebbanburg. It looks good on paper, but I simply don't know enough about wind and tide and current, etc., to know if it makes sense. (Or how long it would take.) Also, for plot reasons, I need a small group to get diverted south, down the east coast, and end up in Streanæshealh.

Let me add that this is around 623, and it's Edwin's band, out on its usual summer ramble: looking threatening, picking up the usual tribute. (I imagine a big, very well-equipped band which prefers to offer overwhelming superiority in order to get the booty without fighting. But they're perfectly happy to fight if necessary. It's just that few groups at this time would be willing or able to even think of matching them, so they'd smile in public, chew their mustaches in private, and dig up the hoard.)

But then Edwin finds out something scary and has to hot-foot to Bebbanburg to protect it. (I'm on very thin ground here, historically. I read once, somewhere, that one of the Irish annals mentions Bebbanburg being beseiged by Fiachnae mac Baetain as a result of his on-going dispute with Edwin over Vannin/Mann -- but I haven't been able to remember where I read that, or which annals. All I've found is a very vague reference in Wikipedia.)

And then when I started thinking of Arbeia/Tinamutha, I remembered Osric. Given that Oswine was supposedly born there, it might be reasonable to suppose that Osric was living there at this time. But what would his relationship with Edwin have been? Would he be living quietly under the radar? Would he be part of Edwin's warband? Would he be a kind of coastal Ealdorman?

I'm feeling muddled. Any thoughts would be greatly appreciated.