It looks like you ordered a builders kit, which does not come with hydraulic hose or electrical connections. It’s designed to mount on your machine in the locations you choose and order the correct size hoses from an outside vendor. For this reason the kits were discounted in price.
I'm considering one of these. One of the many tasks on my DIY list for this unit is to dig up a dozen of 12-14 ft evergreens along my property line. Trunks are around 8" diameter. Do you think this unit would be able to assist removal of the root balls? I plan to use a pick ax and chainsaw were needed to assist with cutting the roots.