I would not cut back either of those salvias now. It is close to winter and sometimes once you prune a somewhat tender plant like salvia or fuchsias they try to wake up and grow and this makes them more susceptible to a winter freeze. Move the plants under the eaves of the house if they are in pots and cover them with fern fronds or dry leaves if in the soil. Around April you can remove the mulch and when you see signs of new spring growth - sometimes as late as May, that is when you can prune back your salvias - if they are still alive. Many gardeners just treat these lovely plants as annuals and buy fresh plants each year. Keep growing, Marianne Binetti