2 different kind of settings for these games. Overwatch is really fast paced and need good bpp to look good. You can achiev that by having a high bitrate. But since your computer wont be up to par with that you need to play on a lower resolution.
Im not really sure if you even should try doing 60fps, but if you do you should try going lower than 720p. If you do 720p try:
2000kbps. 30fps, super fast, bilinear.
Stream or record with that and post log file.