[thejeff]

No, but 20 Jarls out fighting and 20 Gygjas back home researching will do better than 20 Jarls out fighting and 20 Jarls at home researching. Especially since the savings on the Gygjas will let you buy more sacred Neifel giants to go fight with the Jarls.

The better research will let also let you equip the Jarls sooner, raising both their effectiveness and survival rate.

Gygja also have different paths and can thus you summon, forge and site search more than with just Jarls.