OOOPPS!! You appear confused. You say you want to control the speed of the motors in PWM fans, which are ALWAYS 4-pin, and then you ask about 3-pin fans. The Deepcool FH-10 fan HUB is for 4-pin PWM fans, and you cannot control 3-pin older fan speeds with it.
Now, MAYBE your problem comes from the use of "3-pin". It means two VERY DIFFERENT things on lighted fans. 3-pin fan (Voltage-Controlled) MOTORS and 4-pin PWM fan MOTORS are different and require their own correct mobo header connections (and fan Hub systems). 3-pin (ADDR RGB 5VDC) LIGHTS in fan FRAMES are very different from 4-pin (plain RGB, 12 VDC) LIGHTS. You cannot mix the two lighting systems together on a single circuit, so you must match the LIGHTING type of your fans to the LIGHTING header of your mobo or LIGHTING HUB. This is separate from the MOTORS. Fans wth plain RGB or ADDR RGB lights in their frames have separate cables to make separate connections for the motor and lighting units.
So, IF you are considering fans with PWM Motors they WILL have 4 pins for that. IF the lights in the fan frames are of the Addressable RGB (ADDR RGB or ARGB) system using a 3-pin header and 5 VDC power, then that explains why you asked about 3 pins.
If you tell us what fan you are considering - maker and model number or name - we can help more. Also tell us what mobo maker and model you have so we can see how that matches to the fans.