powergaming was much more rampant back than then it is now, unironically enough, due to the way xenos played
1 xeno could reliably take 1 marine out of the round no matter who they were because of the double hugger meta. you could click on a marine twice, or pounce one and drop both huggers, and now they are stunned 4ever
and queen could shit out eggs rapidly at Elite and above (what we called it back then)
on top of that, the T3 castes were p insane back then. you could get decapped in one charge with a helmet on at full HP by ravagers, crushers had a AOE stomp in a 3x3 range + they could charge rapidly, and xenos had macros so they could rapidly switch between abilities depending on their caste, so good spitters could neuro then acid you in conjuction
thats just a small example of the bullshit xenos could pull off, so marines got creative (which got their shit nerfed), marines figured out another way to beat xenos, nerfed again, rinse and repeat