Well, I think if they are part of a group in (rather) close order it can make sense...
They may have formed a shield wall to deflect missiles and to receive the enemy charge.
Then they deliver blows with their 2-handed axes and obviously they would still have their shields with them.
As they would still be in packed formation and now close to the enemy, they have no much room to swing their axes anyway, so the shield is not really a problem.
Of course that would be different for individual fightings.