Fractal does make balancing these cards more difficult. However it is still possible.
Problem:
Fractal triggers pacts more often than non fractal methods.
Solution:
Make the effect triggered less useful to fractal decks than it is to non fractal decks.
The quanta absorption per creature played is a rather inelegant solution but it works. A more elegant solution would be preferred.
We thought about creating the passive ability "Pact": pact destroys previous pact when played, absorbs 1 quanta of matching element when a creature is played, and if you have no quanta of that type it would destroy itself ad would do 15 damages to its controller. In this way, it seems to be a real pact: infact, if you broke a pact, you will pay a "penality". Why do you say that it's no much elegant?
Three reasons the solution is inelegant.
1) Because the consequence is not inherent in the benefit. If the effect triggered was less useful to swarms of small creature than to a few large creatures then the benefit would balance the two combos.
2) The balancing fix feels like 2 separate passives. (the pact destroying a previous pact is not a balancing fix it is a coding requirement)
3) 3 effects is more complicated than 2 effects.
How I would improve this card:
Have only 2 effects (not written in card description language)
1) Pacts destroy the previous pact when played
2) When a creature is played trigger effect X
I would then notice:
1)the trigger favors Fractal > Normal play
2)Fractal favors Small Cheap Swarm > Large Expensive Few
3)Normal play favors Large Expensive Few > Small Cheap Swarm
Therefore I would make effect X favor Large Expensive Few > Small Cheap Swarm. Pandemonium would be an interesting possibility. Large creatures are more resilient. Pandemonium hits swarms harder. However a new effect would be better than an old effect.