Mosh, I can understand it's not your cup of tea, but I still like to stress that both bands did something new with these albums.
Candlemass started the doom metal genre, and they did that by leaning on the slower and heavy (but also "stoner rock") side of seventies Black Sabbath, making it epic in their own way.
Walls of Jericho, Helloween's first album, is everything but generic. The use of such drum style was done in a few songs by other bands such as in Let Us Prey/Call for the Priest by Priest, but Helloween made a trademark of it.
Speedy songs with melodic guitar work and slashing riffs. It's like they mixed the best elements of Bay Area metal bands and Judas Priest, with the melodic wit of Iron Maiden. Yes, my friends, besides Maiden*, there are not that many bands making so much use of speed, tempo changes and melody as Helloween.
This was the basis of the power metal genre. While Kai's voice was rough (and not always 100% on key), he hardly had an accent as many other German singers. And he could scream. A great combination, fitting well to the aggressive side of their music.
Perhaps these albums were not their best, but they were the essence of why we call them the pioneers of the styles they invented.
*And this is also why I am a bit surprised that they hardly get recognition on this forum, although I might be too impatient, because we still have the Keepers albums.