The general concensus appears to be use heavy and shock infantry for the best chance of defeating the Sweboz.

@Ca Putt I would rather stay out of Germany as well but I need to crush them now before the Roman juggernaut starts up. My original plans were to expand into Iberia and take advantage of the lucrative mines there (in my current Carthaginian campaign I am funding 3 Punic and 4 allied Aedui armies from the mine revenues alone) however a Sweboz attack caused me to abandon those plans.

@Geticus, I did not know the temples of Teutatis provided such benefits,, interesting.

With regards to people's advice of simply march through Germania I have a problem with that which I will post as soon as I get a screenshot to show the current strategic situation.