𠌶 and 亏 don't sound similar in modern Mandarin due to historical phonetic changes. They were more similar
in older Chinese.
Character Evolution
BronzeEarly Western Zhou~1000 BCBronzeMid Western Zhou~900 BCBronzeLate Western Zhou~800 BCBronzeLate Western Zhou~800 BCBronzeLate Western Zhou~800 BCBronzeLate Western Zhou~800 BCBronzeEarly Spring and Autumn~700 BCSealShuowen~100 ADSealShuowen~100 ADClericalEastern Han25-220 ADRegularModern