I am using 2 deepcool hubs with 4 4pins connectors works fine with 4 fans total. 

Yup. I reckon that could be the way to go. Thanks for your help. So many options to achieve the same thing - is great to have people to bounce ideas off of.
Thanks again.

Yeah, I still sick those disc things in often enough to install a DVD drive. Each new build I think I can get away with not but inevitably I need it for something (dirt cheap games, work provides software on disc (don't ask why, cause I have no good answer))
Have you ever had any experience with something like the Silverstone 1-to-8 PWM Fan Hub? I would like automatic control based on temp if possible.

Had that thought and went hunting for a 3.5 bay (5.25 has DVD drive) but couldn't find one that would fit while the Silencio front door is closed. Also haven't used then before so a bit apprehensive. Any suggestions on make/model?
Also going to need some extra cooling at some stage because summer is on its way and I'll be looking at some got ambient temps (a/C isn't up to the challenge). Was trying to keep life simple for now, but if fan controller has the flexibility then I might go that route.

After some quick help with fan configuration on a new Ryzen build.

Local computer store recently did 15% off when a complete system (of parts) was purchased - which was awesome so I was down there pretty quick. So was everyone else. They'd sold out of a number of parts I was after and I had to make some decisions on the spot (with a line up of people literally out the shop door).
Ended up with the ASRock AB350M Pro4 which at the time I didn't realise only had 3 fan headers (1 X CPU, 1x 4 pin and 1 X 3 pin).

I already had my heart set on Cooler Master Silencio 352, so that and it's two pre-installed fans are all mine. Due to location of PC the front fan is to loud as it is plugged into 3-pin so runs at 100% all the time.

Was thinking of purchasing a Noctua NF S12A PWM as an extra intake fan on the front (top). Now stay with me here.... I am thinking of plugging it into the 3-pin header. "What a waste of a PWM Noctua" I hear you say. Rationale: computer store has them in stock all the time. They should be much quiter and move more air than the Cooler Master XtraFlo pre-installed. I will use the Y-splitter that comes with the Noctua to connect the other 2 fans (I.e. exhaust fan and front intake -bottom). Additionally if the Noctua is still to loud I have option of Low Noise Adpadter (also included). I'm trying to maximise cooling and reduce noise at the same time, which don't always play nice.

Noctua XtraFlo specs are 0.34A, 4.08W.
Will this be an issue on the 4-pin header (which I can't find documentation on but most people are saying 1A)? Have seen people mention something about start-up power draw is always higher.
Is this all a foolish idea? Am I a genius? Why is this post so long? Will this even help noise and/or temp?

Additional specs:
Sapphire RX 580 Nitro+ OC
Ryzen 1600x
Thermaltake Contact Silent 12 CPU cooler
2 x8GB Corsair Vengeance
Corsair CX550M
Samsung 850 Evo M.2
(remember how I said things were sold out... had to change a few parts, CPU, GPU, RAM, while standing at the counter for what was in stock because if one thing was missing = no discount).

Thank you to anyone and everyone for any help/feedback.