Anyway, it must have been the donation missions then (I did not try those), since I doubt you can hack 5000 merits' worth of holograms an hour.
You are massively overestimating where the "average" player is here.
Getting a module in 5 weeks would require 50,000 merits a week, which would put someone into the top 10% of their Power's leaderboard.
At 3k merits/hour, which is a decent rate for most non-rares activities if you're not doing very specific things or optimising a lot (which the average player, by definition, isn't), that would be about 17 hours committed to Powerplay each week, so 2-3 hours a day just playing Elite Dangerous.
You can get more than you might think. Some stations have 8, and you can hack them all, in and out, with an ops controller. That's 144 per, and if you can find 8 on both sides that's something like 1728 per hour right there. Add donation missions(say an average of 5 per landing, I've seen between 10 and 2) and you've got an extra 1728 from that, as well. That's 3500 per hour without doing anything else. Add to that 200/trip for normal trading, and you're up to 6000/hour just from trading, which is one of the worst ways to earn merits.
Conveniently, the donation missions counteract the rep loss from the hacking.
I don't think it's wise to use the leaderboards as guidance; many players are likely inactive, having pledged and logged off for one reason or another. Others aren't too worried about it.
By 'average', I mean 'the average player who is intentionally increasing their rank'.
Because if you don't care about doing that, then it doesn't really matter if it takes 8 weeks or 16; you'll unlock it eventually, and then have it forever!