if we do it this way then all we would need is to modify monarchy, unless you limit the selection list to the gov types chosen.

if it's just one gov type then all the netters will be concentrating on finding the best possible combination
same for war countries, you end up where we are now, with just a few overpowered strats. we would lose a lot of the strategic depth the suggestion is trying to enhance. players would just select the 3 best pros and 3 least detrimental cons for war or netting or start with a war selection to land grab and then switch to netting selection on land goal.

maybe randomize an extra 2 pros and two cons the player can switch/trade out with bonus points.
the randomizer selects these on creation of country so the player can decide on how to best use these when selecting their hybrid gov types. If provided after the hybrid selection is made then it could prove out to be detrimental with no way out.

alternately just keep the gov types asis and locked in, then let the player select one pro and one con from the full list to be added on with bonus points. this enhancement can also be switched out with bonus points. however this could also destroy the games strategic depth when offsetting a con with a pro and/or using a another con to minimize an asis con.

a randomizer would add an unknown factor ... a player may end up playing a strat they would normally bypass in the game today. the downside could be a player deletes their country to try for a different randomized selection, unless its locked into the account and not the country itself.

the other part is would a player be allowed to switch one or both gov types using current rules.