So, a single guardian came up with a cheeky plan to suck a little light out of your fragments. They succeed. They then fly over to Zavala, who takes one look at them and says "Dur, hur, oh hi there... Ok, fix Titan please, I'll stay here." The guardian does that, so Zavala says "Ok, fetch my fireteam, we're going in rawdog." Why didn't he think of the first, most basic questions - "where did you get your light back?" and - "Will it work for me, the leader of the Vanguard and much more capable as a leader if I actually have my light back?" Seriously, it never crossed Zavala's mind to search for a few more Traveler's fragments and restore the light to the entire Vanguard? Nah, instead this one Mary Sue makes 3, get this, THREE INFUSIONS of light from just one tiny fragment. You know what this selfish piece of -blam- could have done... tell other guardians about the source of light. Then, 3 guardians can have ONE infusion - boom, a fireteam. Search for more fragments, you have an army again. But nah, let's go and glory hound on our own - one man army while the Vanguard risks their true lives just to keep up.