Plz help crafting a staff for necromancer.

I need to craft now +1 to all gems.
Some guides tell that now i must craft beast Farric Wolf Alpha to transform a suffix to a prefix, and this grats +1, but if i use the emulator of craft of exile i cant get the +1 guaranted.
Am I missing something?
Prefix minion DMG
Suffix INT (i dont need it :P)

On bows, if you have 2 suffixes and craft 'Cannot roll Attack modifiers' and exalt slam the item, you are guaranteed +1 gems. However, on staves (including Warstaffs), there are other mods that can roll, such as mana.

Unless I'm missing something as well, I don't think it's possible to craft staves like this any more.