This will sound nitpicky, but I feel as though in comparison between the Security and Insurgent factions on their Intimidate speech lines, the Security faction's Intimidate speech lines are kind of weak and pointless.
I'm specifically talking about Security's "DROP YOUR WEAPON!", "ON THE GROUND, DO IT!", and other lines similar to those two lines. Honestly, how would ordering insurgents, who probably vowed a blood oath to kill til their heads get blown off, to drop their weapons work? And to be meta, it's not like there's a gameplay element to surrender since it's unnecessary for a multiplayer game with a balance of casual and hardcore gameplay and gunplay.
Since the Security faction is technically a private military company, it's not like they have to follow a strict procedure on capturing insurgent soldiers. There can be veteran soldiers doing mercenary work who are filled with adrenaline and PTSD, causing them to get heated against their enemies, so I would believe that they'll be throwing more aggressive, psychotic obscenities to insurgents than giving them a chance to surrender.
I do have a few ideas for more aggressive Intimidate voice lines for current and future Security voice actors:
"FUCK YOU!/FUCK. YOU."
"OH FUCK OFF!"
"DAMN IT/HOLY SHIT, I'LL GOING TO KILL YOU!"
"I'LL END YOU MOTHERFUCKER!"
"THINK YOU SCARE ME?!"
"IT'S OVER FOR YOU!"
"I'LL FIND YOU, YOU SON OF A BITCH!"
"YOU'RE DEAD MOTHERFUCKER!"
"I'LL RIP YOUR HEAD OFF!"
"I SURVIVED WORSE THAN YOU!"
"U.S. FUNDING MOTHERFUCKER!"
"START RUNNING, I'M COMING!"
"RUN, FUCKER, RUN!"
Anyone have any other ideas?