You can normally connect 2 ovens on 1 breaker per the NEC but the manufacturer instructions over ride the NEC per 110.4.B ,
listed or labeled equipment shall be installed in accordance with any instructions included in the listing or labeling.
This means you have to follow the manufacturers instructions. I agree with @JReaf that the control cycling of the ...
You do not have any isolation valves in the picture you included. They would look something like this:
You probably have a cutoff to your unit but you'd have to check with your landlord. Be careful not to mess with the fittings until you determine where the cutoff is and who it affects, it could be for the entire building.