the swords were given out because of the MDES. ME4 is considered as officer so is given sword and when the MWOs converted over to MDES and became ME4, they were given swords as well. since then the MWOs are all given swords to be fair.
you guys sure now all 3SG are given bayonets? i go google search only saw all those golden bayonet.
if true then SAF should retrospectively give out the bayonets to all those NSmen SGT as well. those new birds always get all the good stuff while the old birds get nothing.