Medium height balls in table Tennis in the backhand

Hi i have generally a question about medium height balls in the backhand i have there the Problem that if i do a Backhand topspin on medium height balls that are half Long short and slow that i feel like i can Not generate Speed there and i ask my self If its generally better to Backhand Punch These balls always because i could Just Open Up with Spin with the backhand If i see a medium height ball in the backhand Side just Punch It. Because otherwise i See i struggle a Lot on These ball and i generate No Speed do you think i should do the backhand Punch AS Default on slow Medium height balls and for Sure also on slow Spin topspins of my opponent ?