Question about regression analysis and structure equation model (SEM)!

Hi! Everyone, In regression analysis, if I need to know the total effect of a latent construct, people normally assume that different measured variable in a latent variable are equally important, so they calculate a weighted average and then summed them to create a weighted construct for their latent variable. However, in structural equation model(SEM), I wonder if SEM also treat different measured variables that indicate the latent variables equal too.