Super high bandwidth, super accuracy In Amp not needed

[Flyback]

Hi,
We wish to compare two voltages and see which is highest, and get a rough measurement of the difference. We came up with the attached circuit.
Its cheaper than an In Amp….eg we could just use an MCP6002 dual opamp. Though we aren’t sure. We can’t find In Amps with this ease of functionality. Do you know of one off hand?

LTspice sim and pdf schem attached

 

[kubeek]

Your Majesty, what is Your Highness not sure about? And, what is the supposed ease of functionality compared to an instrumentation amp, if you may bless us with your insight?

Or, if by "we" you mean a group of people, why are you the one asking the question? In a normal world, anyone of the rest of the people would sort it out and you wouldn´t have to wonder about so many trivial issues, but if you really have to be the one who asks the questions on behalf of them...
Are you actually the least inept of them all? What has the world come to?