Blister pack FRS/GMRS radios share mostly the same channels and subchannels with other blister packs. They will function reasonably well for casual airsoft use, provided one's not trying to use a $40 set in extreme terrain and long distances. Their biggest shortcoming, besides limited power, is that they provide zero communication security.
I don't know what you mean by "higher quality brands". For example, Motorola's a "higher quality brand" that produces FRS, GMRS and UHF sets. I think what you're asking is whether the blister packs can share frequencies with UHF, programmable radios (over $100 *per* individual unit, not blister packed). The answer to that would be, the UHF can share frequencies with you because they be reprogrammed, whereas your blister pack is hardwired to only use the frequencies it comes with.
"The Bird of Hermes is My Name, Eating My Wings to Make Me Tame."