Regarding the SEOS kit speakers, the crossover between the woof and tweet is 1.3 khz, so both drivers share midrange frequency responsibilities.
Your broader question about two way vs three way can't be answered in a single forum post, but there are merits and challenges involved in any design, and any speaker represents a balancing act of the designer's specific priorities. As an example, with a three way, a mid driver that spans our hearing's most sensitive range ~2-4 khz can be chosen, thus keeping the crossover frequencies outside of that range. Of course such a speaker will have two crossover frequencies, and the added complexity and cost of the extra drivers and network bits.