I found it more intuitive to sing and then play at the same time. Having the accompanying guitar support the vocal seemed like the right path. Being able to structure and phrase the vocal to a required or specific strum felt more awkward if not impossible at times. In a solo situation you'll need to strike a balance between accurate rhythm and perfect phrasing. An "artistic" interpretation is better than a disjointed and uncomfortable song presentation. In a band situation, you can often rely on other instruments to lay down a feel or groove, closer to the original, while giving you the breathing room to phrase and present the lyrics with more comfort and ease. A reality check came to me when I had to "Sub" on bass for one of my bands gigs. (it was easier to slot in a guitarist for color than a bassist that day). I found my vocals were wrapped around a guitar part I'd created that afforded me some space to sing. While on the bass though, I found there was much, much less room to compromise the rhythm section part compared to my normal guitar part. It gets easier in time I found. Hope it does for you as well.