No, much more. The most of your electrum gain comes from selling cards, which especially messes up the score/electrum comparison. Selling an upped card results in around 1.1k electrum, whereas the match might've given 20-120 depending on the opponent, or much more if they got lucky in the Arena.
Nothing that you can win affects your score. Only EM does, and what rank the Arena deck had that you defeated (if applicable).