Yes, they are actually the one who choose on which exchanges we will trade. In addition to that, I noticed that all coins they were asking us to buy/sell are not presence in other known platforms like Binance.
In my experience, these are the details I sort out for that would make me scared when looking out for a trading group or platform to invest with. I won't invest, trade with groups or follow up with some signal trading groups if you would ask me. Am just trying to speak from a perspective I expected you to have looked out for.
I am not familiar with the platforms you present but, you at OP should know that, its almost nothing to create these platforms and they could pump it just the way they like with flashed coins to make you think your earning while, your money has been lost since the very first day you invested.