Question about Sharkoon Tg5

The fans are all individual, so they are not connected together. If you have enough slots on the MoBo, no problem. Otherwise, buy a 3-to-one connector or a fan controller. Or connect the fans directly to the power supply. Then they just run at 100% all the time.

What is a splitter? In any case, I haven't installed the fans supplied, but these:
be quiet! Pure Wings 2 PWM (120mm, 1x)
Worth every centime.