bourgault primary hose length

i have just purchase 30 ft Bourgault 8910 seeder bar and attached it to a 1330 flexi-coil tow behind cart. Having just completed seeding ive noticed the outside two sections have come up thinner than the middle two sections. The primary hoses going from the manifold to the seeding heads vary from 4.3metres outside heads to 2.6 metres inside heads and am just wondering if anyone else has ever experienced this problem with a similar type of set up.

bourgault primary hose length