Yes but u can decide not to use the bolts on the vampire Lord (& not have Oksana's support if u let her perma-die) & people have still managed to kill him by the skin of there teeth. Yes he was still regaining power so not full strength, but still MC did does succeed (with or without the bonuses to his side).
U can bypass all Trolls but MC can also kill all the trolls if the player so chooses (yes with Goblin or elf backup but still sometimes it's like 2 trolls & 4 goblins).
Dragons are alot like cats in fantasy, they play with there prey. MC was able to survive long enough for her to get bored then talkes his way out of it. Now MC not being able to kill a dragon is believable cos, well shes a f***ing dragon lol.
I reckon MC could take on an ogre. There not much bigger the Trolls. He hasent fought Bolon cos there now on the same team & he dosent Dolf because he dosent want to upset Maghda.
The trolls are human sized... 2 m at most, an Ogre is atleast 3-4 m in size.
Trolls can regenerate but they aren't that much stronger than a human, definately weaker than an Orc and an Ogre turns an Orc into a bloody spot with a single hit in most fantasy lores.
Also let's not forget that Tinkerer displays the MC as an unskilled adventurer that wins most fights by surprising his enemies and fight overhelming numbers in small groups.
He struggles seriously against single powerfull enemies and still uses dirty tricks most of the time to get an advantage... the MC chooses his battles and chose not to fight Dolf directly... I am not sure about the reason aside of cowardise.
I can't see the MC going Full Hero in order to deal with a Monster like Dolf for any reason... maybe if he had the backing of all the guards of weirdwood, but not in a 1 on 1