I'm not sure you can have it both ways there, either it was an arranged marriage and love was irrelevant so the marriage was a sham, or the fact it was arranged is fairly irrelevant and they truly loved each other anyway.

All versions of the stories I know support the latter over the former; the love of Arthur and Guinevere is a byword for chivalrous love leading to marriage, not marriage as something she was railroaded into (if you'll forgive the anachronistic term).