in all seriousness though this should be updated for new things that have been added, namely the strains of xenos- hedgehog ravs and praetorians are the new bane of vanguards. hedgehog ravs can bring a determined push to an ass-grinding halt if used right, because the shrapnel can and will cause either paincrit and bleeding on multiple marines at once, forcing them to stop and pull the shrapnel out. dancer prae's specifically, can be the bane of a good marine push because of how much damage the tail stabs do and the de-limbing they can cause. i've witnessed very good praetorian players pick apart marines solely through short pushes and harassment because they can be very tanky and absolutely will put as many marines out of the fight as possible- whether through wounding or not.
the tools section may need a touch-up but honestly it's still relevant. marines can specialize a WHOLE lot more now, and have access to everything from flamethrowers to the glorified friendly-fire kit which gives them six fucking HEFA grenades, two HIDP, and three HEDP. i've seen decent vanguards be supported by L42 battle rifles with the smart scopes on them, it's good for killing xenos that are either stunned and knocked down and their usefulness is compounded by the fact that they can stay behind the main firing line and support other marines
personally, i've found the M37 to be less useful but that's just me, the delay between pumping and shooting has gotten me killed or seriously injured many times both by praetorians and veteran ravagers, so normally i keep it simple (stupid) and run an M41A with a QF adapter and a laser sight because i'm not huge on attachments, but the amount of fire you're able to put down because of it lets you fuck up injured or stunned xenos pretty bad and provide extra suppressive fire on single