The Insurgent Advisor is really shafted at the moment, and only has access to a couple AKs, an SVD which the Marksman already gets (which should just stay with the Marksman class IMO) and a FAL.
Now, the FAL does balance out the M14 EBR (although the EBR fires faster), but the class doesn't really get any counterpart to either the Security Advisor's SCAR-H or L85A2.
I saw a similar forum post about giving the Ins. Adv. the Tavor and I think it's genius. Makes sense since the Security already has a bullpup 5.56 rifle.
My own suggestion (since I love this gun and I want to see a game actually do it justice cough PUBG cough) is the VSS Vintorez. It would probably balance out the SCAR-H (tbh the SCAR needs a buff; it's basically a glorified AKM with less mag capacity).
I think this would give players an actual reason to play as an Advisor on the Insurgent team because the VSS and Tavor are both actually unique/exotic, as opposed to the AK-74, AKS-74u (why does this class get two variants of the same gun, again; especially when the AKS-74u isn't as moddable as the 74?), SVD and FAL, all of which I'd pretty much expect to be in this type of conflict.