I've never said that any and all discrepancies are OK in the name of game balance. I've simply said that particular "discrepancy" is. Firstly, as we know the game right now, it is completely needed for any chance at balance. Secondly, the "discrepancy" is already handled given that the characters that are strong Force users have been shown to have extra Force icons allowing them to easier win the Force battle.
Did people use to get upset that the old Star Wars CCG use to label any charcater with high ability as "Force Sensitive" even when they weren't? I mean Han Solo is a cool guy but I should have never been able to run him through all those Jedi trials on Dagobah.
In SWCCG, any character with an Ability of 4 or 5 was labelled "Force-Sensitive" on their card. Off the top of my head, this included most personas of Luke (Ability 6 was "Jedi Knight" for Light Side and "Dark Jedi" for Dark Side) and Leia on the Light Side, and Mara Jade, Thrawn and Zuckuss on the Dark Side. I'm sure I'm forgetting a card or two here.
Ability 7 was Jedi Master/Dark Jedi Master respectively, for Yoda and The Emperor.
As far as I know, Thrawn isn't "Force Sensitive", but the game mechanics of having Ability 4 or more on a character were very advantageous for reasons to complicated to properly explain here, but if you've played the game, you'll know what I mean. For Thrawn, it makes mechanical sense because of his tactical prowess exhibited in the Heir to the Empire novels. For Zuckuss, I think they mention in "Tales of the Bounty Hunters" and on the card that he was pre-cognitive or something.
Also, regarding Han and the Jedi Tests, you absolutely could train Han up to Ability 5 through testing. Only Leia and Luke could be Jedi Tested through Ability 6, as the card to do so specifically targets Skywalkers, of which Luke and Leia were the only ones in the card game.
Basically, the Jedi Test was a Destiny Draw, plus modifiers, to reach a target number. Part of what factored into your success was adding the student's Ability score into the algebra to get the result. Obviously, when the Dagobah set came out, "Son of Skywalker" was the popular choice, being the first Ability 5 character in print. All previous versions of Luke were Ability 4.
Also, your Ability score would be modified if the test number you completed was greater than your current Ability score. Thus, for Han, if you really wanted to, you could make a deck that trained him all the way to Jedi Test #5 and you'd have an Ability 5 Han running around afterwards. There were 6 Jedi Tests in total, but as I said, only Luke and Leia could "become" Jedi Knights because the final test only applied to them.
Of course they would go on to print "Jedi Knight" versions of Luke later on, which lead to a meta shift of training Leia with Yoda and having Jedi Luke causing all kinds of trouble elsewhere.
As far as people getting upset over naming characters "Force Sensitive" when they weren't (like Thrawn), I don't think anyone cared, at least not in my experience. The "Force Sensitive' label was really just left in for the sake of consistency I'd imagine. When the Premiere set came out, you had really good "normal" characters with Ability 3 like Han. Luke was Ability 4 and thus "Force-Sensitive", and Darth Vader and Obi-Wan were Ability 6 for Jedi and Dark Jedi status. Premiere only drew from images and ideas in "A New Hope". This was then followed up by the game's first expansion…which was called "A New Hope". I always thought that was such a dumb name to run with, considering 300 cards just dealt with that movie from opening to close.
So going back to the Force Sensitive characters being able to exclusively alter the balance of The Force in SWLCG, I would say having "anyone" being able to do it seems easier from a rules perspective right now. Otherwise, you would have to make a list of all Force-related traits on the cards. Jedi, Dark Jedi, Sith, and Force Sensitive are what we've seen so far. It makes more sense to either say "everyone" can influence The Force, or make a very specific trait and print that on the cards. Either way, it can't be too complex for people to remember. I'm sure this also includes starships as well, so it's probably for the sake of efficiency. You can play Vader's TIE, which I'm sure is implied to have Vader in it, but then you can add a Black Squadron pilot to it as an enhancement, so it wouldn't be "Force Sensitive" anymore.
Yeah, I think the "anyone" thing is probably just loads easier to keep the game moving along at a good pace, and for balance and utility, it means you don't need to focus so much of your deck building on having all this Force-Sensitive stuff running around as a defensive measure. I would say having nothing but Jedi Luke/Yoda/Obi and a bunch of those "Jedi in Hiding" type cards we've seen isn't really the spirit of the movies we remember. Maybe when Yoda spoke of "another", he really meant the dozens of other would-be Jedi that Obi-Wan's ghost should be out networking with, instead of hanging around that kid from Tatooine all the time.