[Rockabye]

They are getting the VIT bonus. The only have 40 VIT. The bonus from level ups is... what, 2? Then 5 from each point of VIT. So that's 120 from 60 levels, and 200 from VIT, for a total of 320... and then I think there's 10 base added onto that, so there's the 330. There's no bug here, but it's important to remember that, unlike characters, summons aren't decked out in +HP equipment/enchants, so it naturally seems a bit low by comparison.