Re: slow progress
Sometimes when we have to look for the education in our training. It sounds like you are training with partners who may not excel in the physicality of aikido; or may not be able to participate in more physical training. If you choose not to pursue another aikido dojo you may need to re-think the learning process. For example, in algebra it is possible to solve an equation with one variable, wherever that variable may exist in the equation. Perhaps you need to switch your variable... Maybe take advantage of what stronger experience your partners have and extract education from those experiences.
It would then become your responsibility to make up the physical training maybe through solo exercises or private lessons. Attract friends to train with you. Sometimes we forget that a dojo is made up of... us. We show up to class and if no one is on the mat it is sensei's fault. We forget it is our responsibility to make the dojo attractive to prospective students and solicit them to train. Sensei may be a lot of things, but rarely is she a marketing guru.
Anywho, a couple of options to consider...