I apologise. I didn't read your post correctly. My previous points all stand but the aircraft you mention have a WSO in the back seat. His job is not to fly the jet so his requirement for a HUD is much less. The back seat of the Typhoon is for an instructor pilot who needs the same information as the front seater.
OK, now I get it. Front and back seaters are both pilots and the two seat Typhoon is primarily a pilot trainer. Now it's making sense to me.n Thanks much.