You won't have a problem, and should use a SPLITTER, not a Hub.
First, I think you have the specs wrong, but there's also a wrinkle in the way those specs are written that helps you. Looking only at the various Cooler Master 120mm RGB fans (you post is not completely clear) for CASE ventilation (not the AIO cooler system), we find these specs on their website
MasterFan Pro 120 Air Flow RGB: Rated Current 0.17A, Safety Current 0.40A
MasterFan MF120R RGB: Rated Current not specified, Safety Current 0.37A
MasterFan MF140R RGB: Rated Current 0.25A, Safety Current 0.37A
So among those the Rated Current, which is the max current each can draw under any normal circumstance, is 0.25A or less. The Safety Current, I believe, is a short-term max that MIGHT happen during start-up for a second or two, and that is NOT a problem for the mobo fan header. It also is likely the value at which some internal current limiter in the fan will trip out like a breaker if that value is sustained over a longer period. So what you need to consider is the Rated Current, and three fans at 0.25 A or less is well below the 1.0 A total available from a single mobo fan header.
So you CAN connect the MOTOR cables from each of those three case ventilation fans together to your only CHA_FAN header using a 3-output 4-pin fan Splitter like this
https://www.newegg.com/Product/Product.aspx?Item=N82E16812423163&Description=coboc%20fan%20splitter&cm_re=coboc_fan_splitter-_-12-423-163-_-Product
or this
https://www.newegg.com/Product/Product.aspx?Item=9SIACJF5497327&Description=fan%20splitter&cm_re=fan_splitter-_-9SIACJF5497327-_-Product
Just a NOTE to distinguish devices. A SPLITTER has one input cable and two or more output connectors, and no other "arms". A HUB has a third "arm" type that must plug into a power output from the PSU, but you do not need that and it's more expensive.
When that is set up, remember to check that the CHA_FAN header is configured in BIOS Setup to use the newer PWM Mode, not the older DC Mode, since you are using 4-pin PWM fans.
Then you have an issue powering the AIO cooler system. It requires two connections to a mobo 4-pin fan header that is using PWM Mode, and that's your CPU_FAN header. You will need a two-output 4-pin Splitter like this
https://www.newegg.com/Product/Product.aspx?Item=N82E16812423160&Description=fan%20splitter&cm_re=fan_splitter-_-12-423-160-_-Product
Using that you can connect both the pump unit's and the radiator fan's motor cables to the CPU_FAN header. There's a detail here you need to pay attention to. The CPU_FAN header pays special attention to monitoring its "fan's" speed signal for possible failure, to prevent damage to the CPU by overheating. But it can only monitor ONE speed signal, so that Splitter will send back to the header the speed of ONE of those two items, and ignore the other. It does this by omitting Pin #3 in one of its two outputs so there is no speed connection for whatever is plugged into that output. Between the two - pump and rad fan - I suggest the most important to monitor for failure is the pump, because you can not tell whether or not the pump is actually running easily, whereas you can always tell if a fan is turning. So, connect the THREE-hole female connector from the PUMP to the Splitter output with all four of its pins, and the fan's 4-hole connector to the other output.
As you say, you do not have any RGB header on the mobo, but there is a Cooler Master product that solves that. Just be sure you buy their device called the RGB LED Controller. (They have a hard-to-find other Controller box designed for the other system, ADDR RGB, you do not want.) You use its cables to connect the box to a SATA power output from the PSU and to a mobo USB2 header, and then download and install the Cooler Master software utility that uses the USB2 connection to communicate with the Controller. This system gives you control of all the RGB lighting devices built into the pump and fans. BUT you have another dilemma. The AIO system has RGB devices in BOTH the pump and fan units, and it comes with a MANUAL control box to feed these two. Doing that would NOT allow you to control those two with the RGB LED Controller box and software. So I suggest you do NOT use the manual system provided with the AIO setup. Instead, get the Cooler Master 1-to-3 RGB Splitter cable like this
http://www.coolermaster.com/cooling/cooling-rgb-accessories/1-to-3-rgb-splitter-cable/
Use that to connect the RGB cables from both the pump and the rad fan to a single output port of the RGB LED Controller box and, of course, plug your three case fans into the other ports. Then all your lighting devices will be under the same control and co-ordinated.
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