Well... technically, when one side is essentially ignoring the rules of the other (i.e. only one 4 or 5-star card), it's essentially cheating. This means that being fair in that case, which does mean no cheating, would be making it easier to win lol. In the case of TT and the NPCs, there is no separation of "fair" and "easy" ONLY because of circumstance. It'd be like someone hacking the game and setting it so they always roll 98 on everything, but not 99 because they think it's "fair" to allow people to win, even if it's a very rare occurrence lol. I don't think anyone would argue that such a situation makes it difficult for you to win, and if the hack wasn't used, would ease your chances of winning.
The bottom line is just that the NPCs play at such an unfair advantage that it serves as nothing more than frustration and arbitrary gating (as though the low LOW chance of getting the 4-5 star card that you want wasn't bad enough). It's not even fun nor beneficial in any way. This would be like SE literally making it impossible for you to win a fight, simply because you got a bad RNG roll upon engaging a boss. Oops, you rolled a 97... you need a 98 in order to remove the invincibility of the boss. Lose the fight and try again. Then when you get the 98, and manage to beat the boss, the game decides that you need a 99 to win any sort of reward. GG, gonna go DIAF.
Honestly though, Random is not as bad as people make it out to be, for what it is. Random can actually be VERY enjoyable when played on even ground (like other players). It can certainly be frustrating, but that's where other rules come into play. The Plus rule complicates things, but makes them IMMENSELY better IMO. The Plus rule is so good, in fact, that it can usually make even Random or Chaos enjoyable. Not joking. If SE is that adamant about keeping the NPCs with only the good cards, then AT LEAST put on additional beneficial rules (like Plus, Ascension, Same, etc). These rules most certainly can backfire on us, but at least it'd make even a 1-star card a potential game changer and give the player a chance of winning a little more often. Plus (and other rules) makes us think, it makes a Random/Chaos game feel a little more controlled (since it's already not, given the NPCs hand), and we can actually have a little fun in the process.
Right now, if we win against Rowena, Landenel, or Swift (among others), it's not going to give us a sense of fun or accomplishment, but frustration. Simply because we then worry about a second bout of RNG in whether or not a card dropped that we wanted. If you don't get it, you're at the mercy of RNG again. Rinse and repeat the 2-fold RNG success every 50 seconds. You'll never look at ANY match against Rowena or Swift, and say "that was fun". I can certainly say that about having played Random and Chaos against another player though. I can say that about either Random or Chaos and another of the previously mentioned rules against another player. But that's because it was a fair match up. The occasionally stupid AI might be the reason why it's set up the way it is, but then they could still just add another rule to some of these NPCs to give the player a fighting chance against RNG that determines whether we win or lose before you even begin.
TL;DR: Fair will always mean making something easier, NPCs need mutually beneficial rules like Plus added to Random, and Rowena is a bitch.