I moved from Canon to Fuji due to weight and having a smaller camera for day to day use. For serious stuff I still have my 5dmk3, 35L, 85L and 300mm f2.8 IS. When shooting sports, I will take canon but Fuji is also working out except no longer prime. These are tools, and not that hard to move from using one tool to another. I used to shoot 2 handed 1 series body. So used to buttons at different places. Same with AF settings. Now with X-T2, your AF settings are like your 5dmk3. I still don't get why it is not working at what you doing. You are NOT shooting low light. Low light is ISO6400, f2/f2.8, 1/60 or so. Yours are ISO800 tops. Now if I were shooting indoor cheer, dance events, I will still take 1 series with 200mm f2 prime. But if Fuji doesn't work, don't sweat too much either. Get back to Canon if you think your work is suffering. Simple. If it was me, I will rent Canon 5dmk3/70-200mm f2.8 and do side by side.