Sigh.
The 4pin header will accept 3 or 4pin connections. Many 4 pin splitters do not. My guess being that analog DC fans used to have much greater draws, some over 0.5A each, so sticking 3 or 4 analog fans on a 3 or 4way splitter was tantamount to a burned up motherboard and guess who gets the blame.
Those Arctic fans take 4v to start, and run at 0.071A. What's the startup amperage?
Op more than likely has an older case. Got a h110m in it, Gigabyte no less. Think it's really got the full supposed 1A capacity? Try closer to 0.8A. What stock fan? Some old junky 0.5A no name brand cheapo? What's the startup amperage on that? Closer to 0.7A?
It's op's choice, but honestly I'd not push my luck praying that every time he boots up the header doesn't fry with overloaded startup amperage. You might.