When working with MIMO systems, you can use sigma to examine a singular value plot rather than a Bode plot.
In this case, the second-order system matches the original 23rd-order system very well, especially at lower frequencies. The first-order system does not match as well.
In general, as you decrease the order of the approximated model, the frequency response of the approximated model begins to differ from the original model. Choose an approximation that is sufficiently accurate in the bands that are important to you. For example, in a control system, you might want good accuracy inside the control bandwidth. Accuracy at frequencies far above the control bandwidth, where the gain rapidly rolls off, might be less important.
Examine the time-domain responses of the original and reduced-order systems.
When working with reduced-order models, it is important to verify that the approximation does not introduce inaccuracies at frequencies that are important for your application.