If one were positing new personal defensive equipment, "stuff that reduces chance of being hit" might be more plausible than "stuff that reduces effect of being hit" barring fairly extreme armor technologies.
Examples of the former that are in the game include -- the flashbang (less likely to be shot at successfully while opponents are blind), smoke (concealment, rather than cover... although laying down area fire through a smokescreen is not an implausible tactic if you have plenty of munitions and you think that somebody's moving *through* it. Plus, do you have smoke that'll block all the opponent's spectra but not your own? Or is it two-way, like thermal smoke blocking IR for both sides in modern-day warfare?).
There's also suppressive fire, but I don't know for sure that it's implemented in any form because the morale model for aliens might not be exhaustively documented in-game.
Toys that might not be completely implausible might include better camoflague (although *moving* isn't going to be good for hiding, no matter what you're wearing... nor is firing something with a nasty heat signature. Firing a PIAT might not give you away, but are PIAT-style weapons likely to still be around?). One could see adding scent and sound elements as well.
For what it's worth, there are presently man-portable fire-and-forget ATGMs that can deliver a decent payload. This sort of thing is an improvement over previous anti-tank weapons, but is also useful for expensively tackling strongpoints without the operator needing to retain LOS for course correction. See the FGM-148 for instance. It is not entirely implausible that this sort of device would be refined in the future with, say, ways to target specific locations using triangulation from local transponders of some sort, providing a safer way to engage known or suspected strongpoints.
It might also be suggested that if one combines present-day research into sensor networks (often DARPA-funded, I believe...) with futuristic nanontechnology, it is not implausible that 'scatter cheap, really tiny sensors/communicators over the battlefield' would be a likely tactic to provide real-time battlefield intelligence. The usual privacy qualms that would normally hamper deployment of a thorough surveillance network might be weaker than usual in the face of a planetary emergency.
