Well I suppose it depends on how long-term the minor non-aligned powers are willing to think when they negotiate with either the Federation or the Pact.
If they were thinking short-term gains in terms of technology and resources, then the Pact is better positioned to provide just this. The Federation has too many troubles of its own with refugees and resources to bother with competing with the Pact to provide minor worlds with something in exchange for allegiance or political friendship.
If the minor powers are thinking long-term however, they might think it not worth it to align themselves with the Pact immediately. After all, before the Borg invasion, given a choice between aligning with the Federation or aligning with some members of the Pact, they would have chosen the Federation simply because the Federation does not occupy, subjugate or conquer and Federation worlds are for the most part independent and prosperous. Of course, over the long-term the Pact itself might distinguish itself as a viable alternative to the Federation and these minor powers might consider starting a "bidding war" to gain as much as possible.
Either way, the Federation has it tough.
Agreed. Given that the whole point of the Typhon Pact story-wise appears to be "let's give the Federation a true rival, rather than a simple enemy", and seeing that the Federation actively seeks to incorporate new members diplomatically, I'm guessing the Pact might indeed start offering "alternative pitchs" to as yet-unaligned worlds. If the story is "world X either joins the Federation or gets conquered by Tzenketh", it's not as complex as "world X either joins the Federation or joins the Typhon Pact". I would imagine the Pact would rather offer peaceful diplomacy than arms to new and weaker worlds, or else it would send them flocking to its rival the UFP.