I haven't played those particular games, nor do I often play games like them, but here's what I say is the crucial temperamental divide I look out for in players even as I'm sitting down at the table with them: competitive versus cooperative players.
A competitive player is likely, though not guaranteed, to be loud, brash, and immediately vociferously concerned with their chances of winning the game at hand. If they have you pegged as one of the good players at the table, they may well be trying to needle or intimidate you already, to gauge your capabilities or gain some kind of psychological advantage. (Some competitive players, however, are just quiet and observant, watching everything like a hawk until they can go in for the kill. These are the most dangerous ones.)
A cooperative player - for want of a better term - is much more likely, in the course of the game, to pursue their own, non-confrontational strategy in an attempt to get a handle on, or just master, the rules. If you know the game better than they do, it's quite likely that you'll beat them (at least this time), because they won't get in the way of your completing your own diabolical masterplan.
The competitive players are a different kettle of fish. You can guarantee that, as soon as they see your strategy start to pay off, they'll attack you with all the force they can muster. It can be a good idea not to appear too obviously "in the lead" at a table with a competitive player. They're quite likely to try to destroy your chances of victory even at the cost of their own - propelling one of the diligent, plodding cooperative players into first place. You have to play much more defensively with these guys on your case - leaving yourself wide open is almost always a mistake!
Of course you may be lucky, there may be two loudly competitive "alpha male" gamers at your table, in which case you can let them show off against each other while you pull steadily towards the win. Just make sure they don't ally against you - that is the worst of all possible worlds!