I was contemplating this today since the rules do not really seem to describe the interaction between fields and horde attacks at all and I would like some sort of abstraction to represent the wieght of numebrs and quantity of attacks directed at a field without adding over much to bookwork or adding a totally different form of damage mitigation. I came up with the following solution:

When a character with a field is attacked by a horde you roll the field as normal, but you add the magnitude of the horde divided by ten to the overload range of the field. So a field with a protection rating of 50 and an overload of 1 is rolled against an attack by a horde with a magnitude of 45 it still bloacks the attack on a roll below a 50 but on a roll of 1-5 it will overload.

What do you think?

Does anybody have a better implementation they use?

Looks a solid option if you're wanting hordes to be more effective vs fields, though to be fair the multiple attacks that hordes throw out mean that it's more likely for one or two of them to sneak through anyway. What is the aim of the change? Is there a specific combination of field/abilities that is proving unbalanced?