The diversity of low-mass cluster galaxies in terms of their size and stellar content is striking. So-called ultra-diffuse galaxies residing in the core of a massive galaxy cluster appear surprisingly intact and might be protected by a large dark matter content. Ultra-compact objects, on the other hand, were proposed to be remnant nuclei of disrupted dwarf galaxies, but no tidal debris is found in their vicinity. The stellar age gradients of “normal” cluster dwarfs suggest that ram pressure stripping played an important role in their evolution – yet that alone cannot explain the systematically different angular momentum content of late-type and early-type dwarfs. In this seminar talk I am going to present our latest observational efforts to tackle these problems, along with comparisons to simulations that can shed light upon the galaxies’ evolutionary history.