I think both are the same.....

both have very much same personalities which is bad for starting a relationships. Shortly they both are too ummm egoistic??!.

Seifer is stubborn, ambitious and arrogant leader, I think he LOVES and likes to help someone who needs him (as leader especially perhaps) like Rinoa.... he wants people to obey him instead of following the rules...... right or wrong. He doesn't like someone who disobey or outwit him. He wants to control everyone, confront everyone who against him and his actions. And he likes something extreme. Like Rinoa's plan to liberate Timber and oppose Deling..... he helped her to achieve it that far.

Meanwhile Quistis is not that different from Seifer. She's just too independent, too confident, very smart, and sometimes can be really bossy if she comes to decide something that no one could argue her..... even us maybe
BUT she doesnt like something extreme, rude, outplanned, stupid and out of rules.... She really knows who she is with her skills plus charm and she has proof for it! On the contrary, Seifer has talent but use it in wrong way and brings him to nothing in the end, Quistis will always pity him instead of love or need him.

I dont think Seifer can start to be interested with such kind of powerful woman either with similar personalities but different vision or attitude in life.
The story would be different if only both had same vision..... and different (or same) personalities.

And Quistis got feeling on Squall not because of something reasonable from my opinion, it's because only Squall that didn't give any attention to her, neither attracted nor interested..... never sharing emotions or talks to her as woman, friend, or even instructor unlike EVERYONE did especially Trepe Groupie. She can't accept that and chase after Squall then..... I do not see that as love after all.... like in the common love stories and movies.... when popular person got attracted to someone cool and calm who ignore him/her existence.

Like Squall says.... Quistis is confusing. He always doesn't not know how to deal with her. Because she is too mature and perfect for her AGE since kid until 18 years old.
Just like Tifa and Cloud. In their childhood, Cloud considered Tifa Cs as immature kids as a result.... Cloud could not befriend with them because no one knew how to deal with him, the mature kid .

Maybe only Seifer (with his bravery) could deal with her but since they have different VISION and ATTITUDE, it won't work for them to love each other...... they can become good friend but not couple.