PoE builds similar to Lvl 1 to Maps - Spark Bloodmage Leaguestart Leveling

Hi, I made an observation I cannot explain: 1) Equip a call of the brotherhood: 40% lightning to cold 2) Equip Spark linked to trinity => You will consistently get all three resonances, even when fighting against a lone enemy. (So it is not like the enemies have different resistance values. My expectation would have been that I only gain two resonances, because for normal enemies the lightning damage is always higher than the cold damage (60% vs 40%) and for lightning-resistant enemies the cold damage would always be higher. How is it possible that for different hits on the same enemy