So the black plumbing is your overflow system?
Joining the two overflows together, and then reducing down through the barb to the flexible hose, is going to severely reduce your overflow's capacity. Also, I see you have a valve on the overflow line. The return pump will set the flow rate through the system, the only reason to have a valve on an overflow is if you're running a full siphon as in a Herbie or Beananimal drain, this doesn't look like either to me.
Regardless of whether the drains are siphon or open channel, I would suggest running separate lines from each to the sump. Also, try to route your drains so there are no horizontal sections, as that can make it very difficult for the drain to purge all the air when it starts. Instead of long sections that are horizontal and vertical, try putting in some 45's or using flex pvc in order to get where you need them to be in the sump.