I have 5 dwarf angels + 1 Singapore angel in my 100g and everybody is just fine. They do need space that's what the 100g tank is for.
I would think that these two angels would work together. The Herald's angel & the bicolor are a little different from the other dwarf angels and in my experience similar to each other. Most of my experience is with the Herald's, however. It is my belief that Herald's angels tend to get along with most other angels & though it's a guess, I think the bicolors may be the same way. I put a bicolor in my tank and he died after 36 hours or so. But during his brief time in the tank he got along with all the others. There was no initial hostility or bullying at all. My coral beauty and male flame took some time to work out their differences.
You have a large tank, it should be ok - but there is always a risk of course... Mixing angels is a new thing in terms of being a widely accepted practice & there's still a lot of "edge-cutting" to do as far as which angels go best with which. Maybe do a search for the 2 angel names & you may find someone who has combined these two.
Mine are a mated pair of flames, 1 Herald's, 1 cherub & 1 coral beauty.
Love that orange around the eyes on the Eibli's - gorgeous fish !
One word of caution - if you float the angel in a bag & the resident fish shows a whole lot of interest in it, repeatedly coming back to check out the fish in the bag, I would not release him into the tank.
And umm... do it on a day you'd have time to tear down the tank if you had to
