The A-series module has a 3-hour time limit to get through, basically, nine "encounters." *
You have three hours.
That's three hours from the start inside the curtain wall.
My players took 7 hours to get halfway through, and then 6 more to get to the end and die.
That's 13 vs. 3 - more than 4 times as long.
How would you get through A2 in the time limit?
I think you'd need some or all of these.
Experienced AD&D players.
Some of my players have played all of the eight AD&D sessions I've run in the past few years. For some of them, that's the entirety of their AD&D experience. Others have players 2nd edition AD&D, 3rd edition, 5th edition. One of my players is an old AD&D vet of mine from high school, but that was Unearthed Arcana era and we used THAC0 instead of the hit tables, simplified initiative (winning side goes and does everything), and higher-powered and higher-statted characters with more magic items than they get now. Only two of my players have independent 1st edition AD&D experience of any note.
So it's a bit unfair to expect them to rattle off stats, know spells, recognize monsters, and have experience dealing with traps and such . . . we found yesterday I could find a rule from memory faster than they could find with "Find" in a PDF. Would guys with that level of play experience back in the day do well in the tournament?
So you really need to know what your guy can do, and have a solid idea of what others can, too, so you can synergistically operate. Any time you spent figuring out what your paper man's capabilities are is time away from that limit. This was a challenge to the player skill and player rules knowledge and player luck, in the end - no awards for role-playing or playing to rulings not rules or using your imagination to expand your capabilities. Some of that might help it along, but the ankheg, the "mummies," and the pit traps are ones that really call for game knowledge to inform your choices.
Especially rote knowledge of spell effects
You don't have time to look up spells and decide - you need to have the knowledge of their limits and powers quite well. My players finished the game with nine casualties but plenty of unused spells, mostly the ones without obvious combat effects. Why? A good part of it is that looking up the spells one by one to figure out if this is a good place to use them is a time waster . . . and you have precious little of it.
A Caller or Leader
Three hours for nine areas doesn't leave a lot of time for democracy, feeling out of options, and collegial discussions. Someone needs to be in charge and make the final yes/no executive decision. You may need to have that person go around the table and take a quick opinion from everyone . . . but they'll need to decide.
For every major obstacle you have 30 minutes to arrive at it, decide what to do, and then execute it.
If the GM has to go around the table asking each person, "What are you doing?" you waste a lot of time. You don't have it.
Decisiveness & Alacrity
You can't waste a second on declaring actions for combat, or making moves outside of them. You have to know what you're doing now and immediately be thinking about next round's actions as this round's change the battle situation. Combat - and other obstacles - must be resolved quickly.
I think if you had all of those . . . you'd have a shot at finishing in three hours. Not a certainty - and the scoring reflects that. But a chance at it. You have to be decisive and skilled at the game of AD&D to do it. Luck bouncing in your favor when it's a big roll, too, is important. It's probably what separated some of the teams back in the day, too. A bad roll here or there can turn a fight in AD&D.
We'll see if my players have more of the above, the more we play AD&D.
* Which isn't nine rooms, or nine hallways, or nine doors - what counts as an "encounter" is sometimes not so clearly defined in the non-tournament versions we're extracting the tournament version back out of! I think if my players read this and try to game-plan around "nine" areas, they'll likely spend a lot of time counting and "saving" effects for "the ninth one, which is the boss fight." Yeah, it might be, but what if you double-counted? Or under-counted?