I'm trying to fit a model for metacognition and wellbeing. I developed an inventory for metacognition and carried out EFA and CFA, and obtained a four factor solution. The well-being construct I'm using for my study has six variables as indicators. However I searched results for requirements of carrying out a structural model and measurement model, most search results gave examples for structural model as having at least two predictor latent variables and one common outcome latent variable. Is there a limit to the number of latent variables required to carry out an SEM? Please help.