Are cybers/spiders appropriate bosses for ultimate doom secret levels?

I've been playing sigil and it had me thinking about monster placement in secret maps, particularly in something like an E1 wad.

Double impact has several cybies in E1M8, not even a secret map.

I don't get why people are always so concerned with putting the things in their maps that they want... Is it just because some rando on the internet might pull an argument out of their ass to make it seem like there were any rules to this stuff? Like "Nooo... You can't put a cyberdemon into any map prior to E2M8, because that's how id has done it. And if you don't do like id, you're doing it wrong." Fuck that shit, man. You want a cybie in E1M1? Put a cybie in E1M1 if you find it fun.

In fact, I'm all for not pretending like it's 1993, and acting like people never saw a game like classic doom before. Every time a WAD starts like a more polished and slightly bigger Entryway or whatever, I feel like my time's being wasted. And that's not so much because it's the lack of difficulty or variety that I mind, it's because this stuff has been done I can't even count how many times already, and I'd rather like to see "fresh stuff" instead of something that I think is redundant. Having said that, if you want a classic doom-hommage, by all means, build it in spite of my personal preferences. Who cares what a single person wants anyway? You need to like what you're putting together.

I wonder what @Misty thinks.

i think something like go2it is better suited as a doom2 secret stage.  warrens was the essential UD secret stage, and it wasnt difficult just psychological and chill.  Nothing wrong with a cyber on e1m9.  nothing wrong with a cyber on e1m1 though.  Thats how you be fresh.  I mean, AA comes to mind...

Meh. If you make an unmodded vanilla megawad, that means you'll have to make barons the supreme bosses of E1, cybers the supreme bosses of E2 and spiders the supreme ones of E3. It waters down the impact of the boss levels if you encounter equal or superior challenges early. 

Overly difficult secret maps with bosses to boot are also unpleasant. Secret maps should be fun and definitely not the kind which make the normal travel afterwards feel drab and inferior. Don't give me a big showdown in the secret map, only to continue with mundane levels up to and including the boss map.