Ohhh boy where do I start
First of all we have Arty and Tate. She's a young, troubled SPG and he's a rugged war veteran.
They didn't get together in "canon" yet but they are destined to be together. They met after Tate's platoon tried to attack Himmelsdorf. He later saved her during a mudslide and they sang together during the march to Italy. (｡’▽’｡)♡
Next we have Fang and Emma. They fell in love while they stayed in the bunker with Tate and the low tiers that they found. But one of the young ones developed a crush on Emma too and he got so jealous and bitter that he told a hostile team about their whereabouts and in the resulting attack they got seperated. Fang thinks that Emma died in the bunker.
Then there's Scarlett, who is currently with Adam. She found him after his team left him behind and they got together. Much to the dismay of Scarlett's ex-boyfriend Striker, who she left because he was really jealous and she doesn't like that. At some later point Striker gets married to Ruth (Goggles' daughter, whom I didn't make a profile for because she belongs to a friend). I didn't figure out the details for the tank/plane versions yet, but in the Utopia human AU they are forced to marry and eventually fall in love nevertheless.
I casually ship Cover and the Sturmpanzer, but I didn't declare that canon. Their chemistry is really cute and perfect but their story would have gained nothing from them getting together (it's just my shipper heart being silly) so I left that as an option for possible later sequels.
Lastly there's my problematic ship, Sierra and Siren. They end up as a couple after Sierra develops a serious case of Stockholm syndrome after traveling with him for several months.
That should be all of them, I think. :Ua