I have never really supported acts from smaller companies, because they lack the capital to promote overseas.
A lot of people think Brave Girls will lead KPop, but personally I don't think so.
Of course, Brave Brother is probably super hyper now. A guy always shooting from the hip, he will probably be thinking bigger future for BG, but similar thoughts were had by the owners of EXID and GFriend respectively.
EXID had one great year, 2015, following the fancam boom but from 2016 it had to rely on songs from LE, one of its members, because Shinsadong Tiger, who composed Up Down, lost his touch. (ST would do the same for Momoland's Bboom Bboom, his last masterpiece) So it slowed down, and by the end its leader and vocalist announced a semi-permanent hiatus.
It remained on the bubble for 2 more years before effectively disbanding at the end of 2018.
GFriend rose because of Yuju's falling incident. At its height on early 2016 it briefly overcame Twice and was the #1 act on Kpop, but by the end of the year twice was way ahead of GF, and the songs of Iggy-Yongbae lost their touch.
GF ceased to be a contender by middle of 2017, and frankly speaking, Time for Moonlight is GF's last major hit. Being bought out by Big Hit did not improve GF's fortune ; it was used as a testing material for the upcoming Big Hit girl group, and this year is GF's final year of contract.
Brave Girls are older, and they have 2 years of contract remaining. Because they have built up a huge following, they will be good for 12 months, and will probably finish their contract. What will happen after that, no one will know, but Brave Brother is a guy of 2000s (he wrote hits for Big Bang, for example, on 2006 and 2007) and he has not had a hit for years. If whatever he releases on summer is not up to speed, then BG will probably meet the fate of GFriend.
I myself do not see it having more success in the overseas than EXID and GFriend, who never really became big outside of Korea. (GFriend's tours are modest and somewhat profitable but not in the league of the major groups)