I would definitely not recommend you thin down the group. the more thorichthys you have,the better your chances of keeping a group successfully.
Infact it may be worth, if possible, getting a few more.
I had 12 helleri that I kept in a 4 foot for a while and I had no aggressive issues.I moved them to my 7x2x2 tank and I noticed an increase in aggression. Nothing to be too concerned about but definitely an increase.
Maculipinnis, (which is what ellioti are now known as)are generally considered the most aggressive of the thorichthys, so you will need plenty of decor to break up territories. It's also good if fish can get out of sight of each other when they need to.
You will witness a big upward step in aggression when they start to breed, Other members of the group soon learn to keep out of the way of breeding pairs.
Your proposed tank offers enough floor space for this to happen.
If you haven't already got any dither fish I would advise you add a group of swordtails. these will also keep pairs busy when they are defending eggs or young.Taking the eye off the other thorichthys for a while.
Hope this helps,good luck.
Thanks for the response.
This is roughly the tank they are going into there is a mound of lava rock holding up the right end of that driftwood and there are 4 more large java ferns on the left now as well. Behind the lava rock is also 4 very large giant jungle val. I am iffy on sword tails or smaller dithers as my bichirs may decide to eat them. (two sens and a gold dust). They ignore my cichlids but fish with a more narrow body shape.... I also have chcolates I have been growing out. The original intent was 5 EB acara, 5-8 ellioti, 1-2 chocolates and my bichirs.