For me, I ditched SAEs ages ago. Ottos are good for clearing diatoms though (I shift them from tank to tank when diatoms come out on the glass)..... shrimps are more for cherry-picking detritius from the moss and gravel.... they are vicious to plants like Rotala wallichi though, as you said. I also have flattened hill-stream loaches, which seem to stick on the glass permanently.