True Eliots range game is better, but then again, thats where his gameplan takes place. Would be weird to be beaten there by a character that doesnt specialise in it.
Eliot has parries, Tina has OH´s, and decent ones i might add (especially 46T) + her tackle off the ground denies a lot of force tech shenanigans, thats what makes her a good choice against Rachel as well. 1p, 44p, 3p, 3(hold)p are very good crushes that can help your defense as well as the now properly working low crush 4k, which is now safe as well.
How many people use her adv mid k hold? I use it regularly, because it only does slightly less damage then the 2 part mid k hold and gives you some sweet frame adv + the possibilty of landing her 3pp (which is safe, if they block) on BT opponents, which leads to a limbo stun + guaranteed launcher. Try backdashing? Eat 6 h+k and strangle hold ground throw for great justice. Speaking of holds, hers are far more damaging than Eliot`s.
So imo her lack of parries can be compensated by having better crushes, actually being faster, heavier (passive defense ^^ ) and having actually threatening holds.
As for mix ups I am not really sure. All I can say is Tina has some string ender launchers (6ppk, 9pk, pp6p, pppk, 44pk, 6ppp, 9ppp) her BT shenanigans, quick access to cb, her kp limbo stun. Every time she launches you, expect to lose 1/3 of your health. Also throws that can decide a match, but Eliot has those as well.
I dunno, I just feel she is a little slept on after her nerfs in 5U. Her 12 f mid has to be respected at every start of a match, also, you dont want to guess and eat a 132 throw.