They are small but active and need the extra space. It is a highly debated topic, but I stand on the side that they need more room. I’ve asked a very experienced breeder about it that pygmies/dwarfs(I believe S&P are included in those) have also stated that they need a 15g.
No, even 1 is very controversial/Risky in a 10g, many reccomend a minimum of a 10 long for them. Your also not very likely to find females and males are very territorial/aggressive towards eachother so even in a 20g you shouldn’t have more than 1 male.