The link thing doesn't work, but no problem, then I'll register.
yeah, the db 604 is possible. I looked at some prototype drawings of other planes, and proposals with jumo 222, 223 and 224 engines, and the argus 413 had a similar exhaust lay out, so these are also possible.
A heinkel 280 is possible. Very possible
the v form in the wings, the tricycle undercarrige, the twin fin.
What if the Germans did the same with the He-280 as the Americans did with the first bell jet?
Heinkels engines weren't available yet. So he couldn't mount them on the plane. Except for that, the first prototypes were ready. Maybe they rolled it out, put some scrap on it to disguise it as some sort of otto fighter prototype and left it waiting for engines, test flight, whatever...
Glue some wood on the nose, bring a fake canopy forward, put on an prop and it looks completely different.
I'am just speculating, maybe the undercarrige isn't the same, or are the fins different or so.
Tom