Follow your mind, without getting blind
Having four wives, only because originator or important individual of some religion or cult had so, cannot be a part of religion. If some such person suffered from coughing, should his followers also develop the same thing in them?
Lord Krishna had more than one wife and beloveds, but his followers never followed the same as a part of their religion, neither he himself talked ever about the same in Geeta.
What Ram did with Sita, after she was brought back from Ravan, and when she was pregnant, nobody approved h this part of his action.
Making such things a part of any constitution is either a product of fear or some compromise or something else which does not add any glory to the constitutional provisions.