So as discussed a little while ago - I wanted to explore in slight more depth what interactions she would have with the rest of her team, and with the peeps from GR1 as the timelines cross and she has likely interacted with a number of them.
This exploration will explore some of the other characters a little deeper, and works on the assumption that the character breakdown earlier in this thread is correct.
1 - Diaz
Diaz is likely the easiest to place, based on the snippets of character she has in the original bio's and the books, reads as definitely an introvert with more intuitive traits (IN--) but it's hard to really pull out whether she's judging or prospecting. She's *most* likely a thinker given her career field and her general cool, detached demeanour, she definitely doesn't take things to heart. In her interactions she does read more as an INTJ - very direct and to the point, whereas an INTP would be expected to be a bit more 'scattered' - i'd have to subject myself to the books again to get a closer idea but for now I'll settle on INTJ.
So this means Diaz and Burke are almost polar opposites of eachother. In just looking at the pair of them without the MBTI pseudoscience that's pretty clear too. As an introvert, Diaz would likely lose a lot of mental energy trying to keep up with a likely very chatty, outwardly energetic and boisterous Burke. On the other side, Burke could perhaps misread Diaz's more serious demeanour and introversion as being upset/displeased at something and either constantly ask if she's okay, or think she's a bit of a "no-fun" hardass.
But, there are in-game references to the two working insanely well when they're together on a mission. Pair that with the two occasionally lightheartedly teasing eachother back and forth, it indicates the two are comfortable sharing a sense of humour. Diaz is a very cunning woman, as is Burke, this is probably what fuels the noted synergy between the two. they both use their brains and experience together with devastating effect. There likely would be a knowledge transfer here from Burke to Diaz as well - Diaz being a marksman/sniper who may stay at a fixed position for a long time, Burke may have showed her how to craft and improvise a few sneaky and rather deadly traps to keep her safe and warn her of incoming danger.
Also add in that they're the only two women in Alpha team, they likely would have spent a lot of time together out in the field. They would've been 'tent buddies' and would've likely had at least a few nights huddling together for warmth to save from freezing their t*ts off. They would've also naturally had eachother's backs on base, and out in the wilds.
At home as enlisted soldiers, unless one of them lived off base or the rules were different for the Ghosts, they likely would've been roommates/flatmates too. So that time spent together would've meant they had a lot more time to get to know eachother than if they were just "in-passing" - they would probably know slightly more personal details about the other that aren't really shared with the rest of the team, such as Diaz's frequent nightmares, and that would've probably led to a more 'sibling-like' bond between the two, where the two understand eachother on a very deep, personal level.
Burke, being older and having joined earlier, would've likely been more of an 'older sister' figure to Diaz. However Diaz, being relatively independent would've relied on her less for mentoring than perhaps other female Ghosts. But Burke would perhaps still feel rather protective, even if this was quietly so. While Diaz may have helped Burke to slow herself down and understand that its okay to need some space to think.
On the negative side, there's a good chance that a misalignment of "smarts" exists between the two - Both women are probably very intelligent, you kind of have to be to join the special forces and last longer than 5 seconds, but Diaz is by far more academically intelligent than Burke who was likely average at best. This could have contributed to some feelings of intimidation/inadequacy or on the flip side, could have led Diaz to become impatient with Burke's apathy toward such subjects or slowness to grasp what she thinks is a 'simple' concept - this could've led to some slightly more heated discussions or straight up falling out, but they likely would've mended it over quite quickly. The chances are both would've valued the other's respective intelligence, but there is a large vector for misunderstandings and loss of patience in this particular discussion sphere.
Similarly Burke may very quickly and easily push Diaz a little too far sometimes and this could lead to a rather snappy response or pushing back, but manifestation of both of these two negatives would've likely been few and far between by 2011/2012
Bottom line/TL;DR Burke and Diaz would've been incredibly close and rather sisterly, despite their differences.
That's awesome Burner, it's the crashed plane mission! I loved sniping the kidnappers through the house upstairs window. there was always one guy left inside that got me at the top of the stairs though!