What is the realistic lag or lead copensators?

Dear colleagues, I am designing a multivariable controller for a plant of 3 x3 transfer function matrix based on Inverse Nyquist Array method where I propose compensators matrix that reduce coupling between outputs, and then a single-input single-output theory could be easily applied (in terms of mathematics called diagonal dominant Q(s) transfer function matrix , Q(s)=K(s) G(s)). As you know these compensators consists of RC networking and should be designed and manufactured with realistic and reasonable sizes of resistors and capacitors, they should not be too big, like dimensions of tens of centimetres or bigger . I have managed to obtain Q(s) as diagonal dominant with specific compensators matrix, but the question is whether these compensators are realistic or not. Kindly advise how can I judge that these compensators are realistic or not( compensators matrix is attached), I have been informed by one of the field colleagues that the ratio of pole over zero should of a compensator should not exceed 10, but what’s about compensator with more than one zero and more than one pole? Any rule that can be employed to determine whether these compensators are realistic or not, what references or text books are available that can be reviewed in this regard?