Hello.

Dragonic site has the highest requirements but has probably the worst spawns due it has so many h.a. spawns.
Therefore it would make sense to change spawns there.

One possibility would be:

 

Super Rare:
Charmander. Is not a dragon but Charizard and both mega evolutions look like one. X is even dragon type. Fits good enough imo. Can also be Timid or Jolly and Adamant which would play in hand to make the exca viable for more than one sync. Needs no h.a. as well.
Deino. Needs no h.a., is a still somewhat good PvP Pokémon. Is not a op combination with Charmander I think.

 

Rare
Swablu instead of Goomy since Goomy would be pretty much worthless as you'd never pick a Sassy or Modest sync here.

Noibat Same here.

 

Common
Axew. May seem a bit op to put such a mon in the common category but tbh., noone wants this mon really except story players. Its not very good in PvP and has no big money value.
Tranpich. Was already here, fits.

 

Uncommon
Horsea. Was already here, fits.

Magikarp. Good replacement for Rhydon which has nothing to do with dragons imo.

 

Those spawns are better compared to other excas, which is okay for me since the requirements are the highest, and then it also should be a better site.
On the other hand noone ever said that every rarity needs to have a pair of Pokémon. Could put Axew to rare and have 3 rares and 2 common ones for example.

Open for suggestions to optimize this spawns. I just want to make smt. move to change the bad Dragonic site spawns.
 

+1, Excas in general need a massive overhaul.

i like the spawn in draconic site but if a rework will be added i hope result in new excavation sites