Go for a broad selection of ex players of different positions and managers, ideally those who have not played/worked together, who also have no current professional affiliations with clubs. Along with ideally past evidence of having the ability to be objective when assessing a situation. Its rare but you will see players acknowledging controversial calls that go against them as correct, i feel this is a pretty valid proof of some form of integrity towards the game and would be able to add to the conversation about rules.

Right now we have many pundits [normally ex-players] with varying opinions on the rules, but there are some rules that they do all agree on as being bad for the game. These are new rules that haven’t always existed in football that were created by people who don’t have the same experience of the game as players who have played at the top level. I think getting them in to help with var is not the best decision right now as they have different opinions of the current rules. Maybe it would be smarter to have them as consultants for when Howard Webb and co want to set the rules for the new season. Once the rules are set you cant argue bias as everyone is playing off the same rules. Maybe after doing this have the players also consulting with var as a separate entity, to help create a interesting dynamic for the “separation of power” as mentioned in a comment below, something else i think could help with avoiding errors