Umm, a longsword vs larger target is d12 damage. Two hits, without any bonuses, is still max 24 points of damage. Enough to kill an average ogre. Or, as
@Lanefan put it, certainly not unreasonable.
And, yeah, look at that encounter. Two fireballs and poof, encounter over. Like I said, 42 hp giants.
But, hey, keep proving me right by pointing to the extreme examples of encounters in modules as to how lethal the game was. It's funny. Gygax complained about how many players were hitting double digit levels, back in the 70's. I wonder how they did it if
@Sacrosanct is right. After all, according to him, no one should have ever advanced past third level in all the years of gaming.
It's like the "slow progression". That's another myth. The DMG actually flat out states you should be hitting name level in a year of gaming. 2e? Oh, ok, fair enough. No xp for gp? Yup, that's going to slow advancement to a crawl. Totally fair. But AD&D? Naw, you yoinked up levels quick as you please.