I'm not saying they *weren't* copied, but think of this... you want to carry 90 passengers, there's a fuselage arrangement that's most efficient for the job. With that fuselage, and the range required, there's a wing profile, span, and sweep that's most efficient. There are horizontal and vertical stab arrangement and sizes that keep an efficiency window, as well as engine thrust and placement, and with engine thrust requirements come engines of a particular type and size.
It's really not surprising at all that two aircraft intended to do the same job could end up looking very, very close to each other. To the untrained eye, it's like cars; four wheels, four seats, four doors, engine up front to absorb impact and driving the fronts to save space. Trunk in the back 'cause that's the last place to put it. Aero shape: Voila, the modern "jellybean" car. If you didn't see them every hour of every day you might have a time telling some apart, too.