Yes, it would be too much, but even if it wasn't, I would not put angels or gourami in with these fish. Silvertip Tetra
are known to fin nip, and this can be aggravated by small spaces (a 10g is small to this fish) and too few numbers (six is minimum, more would be better, but not in a 10g). Plus, the long fins and sedate nature of angelfish and gourami is too much of a temptation. Even Neon Tetra
are known to become nippy under the above conditions too.
To the space issue. There is insufficient space for Scalare Angelfish
, but one Dwarf Gourami
would work but not with the present tankmates. And here we come to a quandry. Both need more added, but this will not work long-term in a 10g. You could manage with just the neons, with 6-7. Up to you where you go from here.
Do you know about our fish profiles? Second tab from the left in the blue bar across the top of the page. All these fish are included, and the profile explains numbers, tank sizes, etc. The names that shaded you can click for the profile.