Hello.. Yes ur dental surgeon advice is perfect.. the treatment plan suggested by him is correct..
Horizontally erupting third molar/wisdom tooth should be extracted on diagnosis.. as it may create trouble in future..
regarding 2nd molar...if pulp of ur tooth is infected irreversibly or degenerated..... if ur radiograph suggested periapical pathology/infection, or ur clinical symptoms suggest pulp degenration then its treatment is definitely RCT which is treatment of infected canals of the involved tooth.. and since RCT treated tooth gets brittle after few years so to prevent its fracture
we give it crown/cap..
and both the tooth are different.. removal of wisdom tooth will not treat the pulpal/periapical infection of second molar.. so it has to be also done..