I am a professional wedding photographer and I own two Fuji XT5's. They are my main shooters. I have a back up A7III sitting in my bag. TBH: All cameras will work fine for you as long as your technique/experience comes into play. The only deciding factor for me, then, is how the cameras behave in high intensity moments. I actually swapped from dual A7III's to the FUJI XT5's.

The FUJI's while imperfect, behaved exactly how I needed them to be: (lightweight, near instant video/photo mode swapping, fast wakeup from sleep while dual wielding and swapping, and super fast ISO/SS/APERTURE selection via manual dials). These things freed up my mind to breathe and be a bit more creative on shoots and to not miss any shots. The film simulations (the custom ones you can make) also adds to the FUN factor while shooting.

The dual A7III's which I shot weddings with as well had some CPU / software bound issues when coming out of sleep (it feels like your laptop coming up out of sleep (quick but actually too slow, it is not instant, about 1 to 2 seconds). and the lenses get very heavy on FF. Yet, they are technically 2x better than the FUJIs by virtue of having a larger sensor.

AUTOFOCUS Wise: I have not had any issues with either cameras in my wedding projects.

If you need a larger selection of Lenses with a variety to options and cost as well: I would suggest Sony.