high-urgency isn't a *frequency* per se. it's a flag you can toggle on cards, entirely separate from the frequency setting. basically, if there are eligible cards in the high-urgency deck, you draw from it instead of from the normal-deck. but if there are multiple cards in the high-urgency deck, frequency governs which gets picked, entirely as normal.

i assume storynexus decided on this implementation so that you could have an activity where *every* card is high-urgency, except for a single low-urgency fallback card for if you've managed to lock yourself out of being able to draw all the others.