The reason old AST felt very random was an imbalance between all damage buffing cards more than anything. When they finally got to reduce it near the end of SB with Spear being buffed up and Balance toned down a little the job suddenly became a bit less frustrating with different card options. Otherwise what generally helps reducing rng frustrations is reaching a good balance of control tools for the player to play around said rng, which has been found in many tools like MCH ammo, RDM acceleration, AST royal road, BLM sharpcast, etc. Rng inherently introduces skilled play with priorities and how to adjust to rng results at all times, but agency tools also add up skilled expression on top of it, which is a win win scenario as far as I'm concerned.

Obviously, when there is too many control tools, like BLM past HW with a craptload of sharpcast and even paradox vs very little rng generation (thunder of F1), or too little control tools like HW MCH where you could end up spamming split shot during mildfires, it's no bueno. AST had a solid control tool baked in with royal road which already accepted back then that if everything went well, you'd prefer damage cards, and recycling support ones was designed to seriously buff your damage cards. All in all if your goal was damage, then you had all the tools to ensure you could exploit this, and as I said previously, the only thing that worked against this was the imbalance between the Balance and the rest of the cards. If anything old AST rewarded skill expression very strongly, and SE didn't like it. It wasn't that much about swing rng (even though there was due to card imbalances).