That ball head adapter is too short. I know because I tried it with my EXOS-2. The dovetail clamp on the EXOS-2 will not allow the camera/lens to be moved forward or backward when balancing the mount.
You want to find a Vixen style dovetail with at least 10 inches in length that will allow you to move the camera/lens forward and backward to balance the DEC axis. When you balance the camera/lens for the DEC axis you will find the side with the motor on the DEC axis will be heavy and the camera/lens will want to rotate in that direction. You can try to mitigate that that by adding another dovetail on top of that to form a + (plus) sign and mount the camera on the opposite side. I do not recommend using a ball head because it will move. You may not see it happening, but it will move. And last but not least counterweights. Depending on the weight of your camera/lens you mat not need a counterweight to balance the RA axis. You might not need the counterweight bar. Just experiment with various configurations and don’t be surprised if it takes up a whole day. If you think you need a counter weight you can buy a 7.5 lb Skywatcher counterweight. Just make sure the borehole is the correct size. ALWAYS have a hand very close to your equipment, so you can grab it when balancing the RA and DEC axis. You do not want to have your equipment strike the tripod of the mount and damage your equipment.
Mounts: ES PMC-8 G-11, ES PMC-8 EXOS-2
Scopes: ES ED127 FCD-100, ES Levy Comet Hunter, ES N208CF, QHY Mini Guide Scope, Solomark F60 Guide Scope
Cameras: QHY600M, QHY128C, QHY168C
Misc: MoonLite CFL 2.5 / High Res Stepper / V2 Mini Controller, Baader SteelTrack NT / SteelDrive II, Baader UFC, Optolong 2" L-Pro / L-eNhance, QHY CFW3-L, Baader 2” LRGBSHO CCD
Imaging Software: NINA, APT, SharpCap Pro
Processing Software: PixInsight, Lightroom, Premiere Elements