You're arguing for laziness, where there's more effort. The blanks don't just have to be a certain weight. They use a balanced metallurgy that is difficult to get right - especially as most peoples in that time and place had lost that particular level of skill.

If you reject abstract from Celtic culture, you reject the Celts. The Dagda isn't exactly some solid figure. They're an artistic people, in everything from their laws to... Their coins.

And as most family meals also intentionally left one part unfinished... For a deeply spiritual people, maybe you shouldn't be rejecting it out of hand.