Okay, you get a point there
. But on the other hand, these skirmishers will normaly get a panic check (at LD 5 or so) and should be then often below 5 models. Also, other skirmishers might get panic too.
Taking a panic check depends on the size of the unit and casualties caused. I have experimented with very large units of skirmishers (up to 30 in a unit) whose function in an army without cavalry is to block enemy cavalry from attacking my flanks, they won't win but they can FIBGO and stop the cavalry that way.
OK so lets assume that berserkers hit skirmishers, at 25% casualties the skirmishers take a Ld test. On a Ld 7 they are going to have a 50:50 chance of passing. Wipe the whole unit out, points are scored but no test and no one else will worry. But lets assume they fail the test and run, they have to end up within 4 inches of another friendly skirmisher unit (which does not outnumber them 2:1) to worry anything else.
So taking all that into account, I feel that berserkers lured into cheap skirmishers is a waste of the berserkers.
On the other hand, when I first started using Vikings it was against Nomad Horde armies, now expensive skirmishers are an entirely different matter. But Vikings are still a very good army, as my opponents at Warfare will find out at the end of November.