Let's hope that the 1:10 ratio of soldiers:prisoners works out. If it doesn't, I know who to blame (not that I'm likely to hold it against you).
Horses can be loaded into ships, it's just not necessarily easy.
And, as I said earlier, there are no good options.
Those 10 men are guardians as much as guards. Joral can tell them they'll simply be lynched by angry peasants if they escape.
As for horses, William I obviously did it in large numbers. He alone had three horses killed under him in Hastings, so they brought enough spares. William's boats were shallow drafted and beached on shore. In the last battle, the Duke captured a great number of longboats, which are also shallow draft. Those are good for beaching quickly and assaulting from sea; unfortunately, they probably do not have specific restraints for horses like William's boats. They'll just sink if horses panic inside them. We have no capability similar to William's.
I'm thinking a set-up like this: Put the horses in a few cogs, our men in longboats. Sail to the settlement and beach the longboats quickly, using surprise and the similar appearance to their own craft to gain the beach-head; and then ground the cogs in probably 10 feet of water and prod the horses out of the hold and into swimming a shore, cogs lighter and drawing less water now, crew anchors and disembarks into skiffs.
It's a lot of work for those horses, but an enemy that fights primarily with shield and axe will be easily broken up by charges. Worth the herculean effort, imo.
Of course, I'm also okay with simply riding to the Duke.