if you do go for Roos next, i'd cancel the ivory trade ASAP (10 turns). he has no horses, and Surey has no spares to trade even if they become pals. if Roos can't make mounted troops at all, you can bring more zerkers and save the bother of making/transporting more spears/pikes. you'd lose 1

and 4 gpt, not a problem (your sickest city is 5 over health cap while you have the iron trade going).
but I'm now kinda leaning towards attacking Bismark.
...
Possibly he has some wonders or something
Bis has Statue of Zeus. F9 doesn't show where it is, but you can see it in Berlin if you zoom in on the city. he also has Angkor Wat, i don't see it on the map but it's not a warmonger wonder so big whoop.
Also you should note that Hannibal has settled on an island south of his main continent that has Iron on it. It's in Ice and Tundra so it isnt an appealing city site, but it's only a matter of time before he hooks it up and cancels your rather lucrative trade (3 health recources, 2 happy recources, and 7gpt for one stategic recource is incredible, imo).
hannibal will have access to copper and iron on that island, and horses on the island next to it, once horse city gets a border pop. but when we get privateers that map setup is perfect for us and hell for him. we can use blockades to deny his mainland cities access to
all of his strategic resources using just a few privateers, even if we're at peace with the guy. seriously, 2 or 3 privs to blockade plus whatever backup we decide they need. and we can
keep denying him access even after he gets astronomy, because trading by ocean instead of coast wouldn't save him while we're denying him at the source. he'd need astro + chem for frigates to be able to stop us. yarrrrrr.
isabella has one source of iron. i have no idea whether he'd demand it off his vassal if we stop our trade and he can't actually use his own, but the option is there. hmmz, i don't know whether he'd cancel our iron trade once he thinks he has his own, even if he can't use it due to perma-blockade?