So it was either Second Age or stuff earlier in the Third Age, which does have some potential but doesn't build up to a climax the way the Second Age does - or rather, it does but that climax we've already seen in the films. But yeah, the idea was that the Second Age is a big sandbox in which they'd have to make up lots of the plot themselves as there's so little written about it, so it's bizarre to have Isildur already in the third episode. That's really a lack of guts and confidence, going for the crutch of the familiar names already so soon. As was making Galadriel their heroine rather than some Elf they'd made up themselves, for that matter.

For sure they had to compress time, they were never going to have a series stretching across thousands of years - but they didn't have to do it to this extreme extent.