My friends and I discovered 40K this winter, and have started out with very different, small armies. There is some disagreement on how to create a "fair" match-up. What do you all think about using Points and/or Power to calculate fair match-ups; and if either of those are important, how close to those scores need to be to be "fair" (e.g. Power within two; Points within 100, or 50, or 10, etc...)?

All of us are brand new, so there's really no subjective balancing of "skill."
Thanks for the opinions (or straight up facts)!