where you buy necromancers?
 

im level 10 paladin i need powerfull warriors, where are the shamash and necromancers?

Shamans are probably in the Orc embassy, finding necromancers is just pure luck, if they aren't in the cemetary or any haunted ships/crypts then you might have to wait a long time for them.

there is one necromancer in Kordar - hwo often has (not always) necromancers - apart of that I nearly never found necromancers sooner (when very lucky, than vampires in the swamps... but necromancers? pfeew... tough luck!)

Next stop if Kordar necromancer is not the lucky ace: Demonis -> there are very often necromancers for hire... If even this failes:

In the underworld (in elven lands) are necromancers nearly totally always (as this game is random in huge extend I would say that there might be 1% chance you won't find them even there... still I am rather optimistic)

Also you may reconsider if necromancers and shamans are totally so powerful as you see them to be.

For the orc ambassy : You need to win the orc battle to gain access to the recruit units - prepare for tough fight :)