GAS to be around 300 speed. Pretaunt protects From cooldown reduction, GAS then goes and lowers all cooldowns aside from DR & Malak. My working theory is that GAS needs to be faster than BSF. Thrawn or R2 might work for HY. Especially if Thrawn is faster than BSF and swaps to GAS so he can go before BSF.
HK47 prevents tm gain for those with protection up, but the attack tech also lets GAS ignore defense which is critical to take down Malak and in general hit them hard. Once GAS loses protection up, he will get the tech tm gain. A fast GAS is needed initially so he can take enough turns while it is being blocked.