The way this Deltritus session has started playing out is very true to form for Homestuck. More specifically, it's playing out like Act 5 Act 1. Additionally, the arrows consist of three equals signs (===>). The logical conclusion is that there's a six-player Nymph group and a matching six-player Satyr group, that will end up combining into one session.

However: let's dive deeper. Rose and Dirk are competing to see whose species will be the ones to play. At no point does this mean they have to formulate their strategy around the same type of session. Rose has picked to model Alternia (custodians, prophecies, weird biological stuff) since that planet had a fairly typical successful session. Dirk has no obligation to match Rose's style here; he's trying to beat it.

I am proposing that there is one Satyr. Or at the very least, one who is set up to play the Game. Dirk will be using Caliborn's dead session for inspiration; having created a single perfect being capable of soloing. This relates to how Dave was raised up/destined to be the hero. But if Rose is carrying the Alternia stuff herself, why six Nymphs instead of twelve? Well the easy answer is that there's six relevant trolls. If we look at the broader picture we get an even more fascinating numbers game at work.

We have 4 kids from Earth C (who represent the Earth session from Homestuck 1), 6 Nymphs (evidence-supported hypothesis), and 1 Satyr (wild guess). That adds up to 11 potential gamers. The number 11 corresponds to Crocker. Jane is obviously going after her child. And her journey to Deltritus is going to very much resemble a different Crocker invasion. And this time, Dirk can in fact blame himself for it. Not entirely, but he definitely stoked the flames for Jane to become an inter-timeline warlord.

For those still reading, I have one even wilder claim to stake. We've already seen sprite^2s. For 11 to become 12, we shouldn't rule out the possibility of somebody who has already participated in a session to boot up the Game a second time. With SBURB's themes of adolescence, the odds of this are startlingly low. However, if there was one character to do such a thing, my guess would be June Egbert: professional outlier. She's developed a knack for doing things beyond the scope of other characters over the years.