Your spokes should be sized for the rim so that you don’t need to trim the spokes. Rarely should they have to be cut/trimmed. How is the radial, lateral and center true? What is the location of the spokes that seem too long? Sometimes the wheel has been curbed and needs to be pulled to fix the radial true. A quick indicator that spokes are too tight is when you can see the metal stretched upward around the nipple(s). It would be nice to see pics or a YouTube video of the wheel as it spins.
There needs to be even tension on all spokes. If there is less tension in some spokes, but the wheel spins true, the hoop is bent.