Part II is not so easy with the little green token that can reach 0 and moving each time there's creature on earth cases and more on the 3 specific one. Also, there's less gold to buy power and the sea crature are stronger. There's not way that you can take down a SeaTroll with 2 players on legend 7/8, even with the Alberan upgrade.
Are you sure you not have forgot something in the rules ???
We usually do not loose fights against ordinary monsters. Therefore one of the more important things in Andor is to know when you can fight which opponent.In earlier legends you fight the weaker monsters and ignore the heavies. Later on you can also figth Sea Trolls with two heroes and the ship upgrades quite easily.
Just keep the fame track in mind and try to prevent the heavies from jumping...