Demanding any constructs to be equal to the summoner is rather greedy, isn't it? You're adding another combatant. Even if it's weaker than all the others, it's still quite the advantage as long as it doesn't instantly die to random AoE.
Like, in card games along the lines of MtG, suppose a creature that summons another. If each of these eats a card from your opponent to deal with each of these, playing the single card generates card advantage—having more resources left. They also have to spend time dealing with your extra threats if they demand extra answers—so you gain tempo. There's lots of famous cards like this. In Ling Qi's system, if Ling Qi summons the worms, assuming they're durable and threatening 'enough', they can generate an advantage (in terms of qi or spent actions), even if they're not precisely an equal to her or her opponent.
Against an opponent with mostly single target answers, the worst case scenario is Ling Qi coming out even on actions, down on qi—this demands that the worm be one-shotable by the opponent and that Ling Qi only summons one worm. Given that Ling Qi has unusual qi reserves and acceptably Darkness-focused expenses, even this is not exactly a bad scenario. If Ling Qi spends 6 qi she gains an action against this single-target focused opponent, which is immense; not to mention that the extra worm got an attack off. Regardless of the outcome of that attack, Ling Qi's use of Crawling Horrors is a win.
Against an opponent with AoE answers, but AoE answers insufficient to oneshot the worms, then Ling Qi gains actions and is even on qi, and the worms can even get a chance to attack, at which point the worms have had actual tangible effect on the battle, which is either an opponent being grappled (and becoming easier for all the other effects to hit, ignoring any Ling Qi allies) or applying multiattacker penalties in the absolute worst case.
Against an opponent with AoE answers sufficient to oneshot the worms, well, this is clearly the wrong tool for the job. Just make them become lost with the new Elegy tech, so that they can't afford to do their blasting job without hitting their own allies, and don't swarm a blaster. This scenario is only relevant, then, if Ling Qi is not aware of her opponent's answers.
While that is going to be a reasonably common thing, especially in the wider world, partial-information games like battle are not unbeatable, especially if Ling Qi begins to play the information game more.
Crawling Horrors is an important part of Ling Qi's toolbox. Opponents without clean answers either get bogged down by the worms or use up actions dealing with the adds, and opponents shown to have clean answers can be whisked into the nightmare realm of Ling Qi's personal Encircling Winds attention, or just lost conveniently on their way to the battle.
