I guess it's nice to know the "value" your snakes are getting but that is relative to what? Fat, protein, calcium figures shown are good but since we really don't know what the needs per say are for snakes ie balls then your basing it on what we has humans require.
Who's to say that snakes may need a higher protein or fat content then we do.
Until there is some type of study done to show just what the daily,weekly requirements are than I guess it boils down to what ever gets you thru the night.

Rats, mice, etc. feed them what they will eat. You can raise and maintain a healthy bp on a diet of just mice or just rats or both.
And in the end isn't that all that is really our goal and important.