You can fit upto 154.5mm tower coolers comfortably. It also depends on the position of your CPU socket - if its further to the front of the case, you have an extra 1mm. Towards the back of the lid, you have those square punches in the lid which messes with giving absolute measurements. In my case with a 2700x in an MSI B450i, I have 155mm.
As better examples, you can fit a Thermaltake UX200 (152mm) comfortably, while a Deepcool Gammaxx 400 v2 (154.5) just fits. The Gammaxx 400 GTE and Pro models (156mm) will push against the lid.
The Noctua UH12S will not let you close the lid (159mm) else you have to cut holes for the ends of the heatpipes.
According to their website, the Scythe Fuma 2 is 154.5mm, so it should fit. However I can't find any technical drawings of the heatsink itself unlike the above mentioned coolers. That really helps in gauging compatibility.