As for the end battle scene.... we have moved back into the late GOT era school of tactics. So the master plan is to send Damon out alone....hope he doesn't get instantly killed by hundreds of arrows (and of course he doesn't, because that late GOT era plot armor is back on the menu), and somehow this will coax the enemy to send out their entire army. Because.....why would they do that exactly? For all accounts the Crab guy (can't remember his name) has shown himself to be a cautious and shrewd tactician, able to beat a superior force that includes dragons. Hell the entire battle scene we see how paranoid he is about dragons, constantly checking the skies. Yet when he has Damon dead to rights, instead of...you know.... having an archer just finish the job, or send like 10 guys to surround him and take him out....he sends his whole army because reasons. It makes no sense, it's an incredibly stupid plan...and if we were back into early GOT logic.... Damon would be food for the crabs at this point.
Now if they had gone with what it first appeared, that Damon had gone rogue and took an insanely risky gambit that just let him get close enough to the Crab guy to take it out....I could buy that. Damon seems the type that would easily rather go out in a blaze of glory rather than have to bow before his brother again for bailing him out.