A terrible map in my opinion. Everything that is bad about Team Slayer, is present in this singular map. But seeing how it has a ridiculously high percentage in the playlist (at least it seems like that), I guess there is no avoiding it.Okay. First off, Opening Push. Something that is annoyingly important on this map.
Elbow SpawnYou instantly have the advantage. You want to have someone contest for the Invis. A good way for this player to turn the battle in their favour is to pick up the Brute Shot and spam some shots into the doorway followed by a prenade. If this is successful, the Camo Guy should back off and try and make his way over to top blue to put pressure on the opposition from the bat.
One player should remain on Elbow to spam nades at Blue Window and watch Snipe Lift and put shots on players trying to make a quick S3 push. If you are this player, put as many shots into them as you can.
The remaining players should go up to S2. One getting the Snipe and the other 'baiting' Overshield. In other words, waiting for someone to challenge and getting that 5 second invincibility boost for an easy kill.
Bottom Blue SpawnAlways a sinking feeling when you spawn here. Again, contest for that invis, send one guy to go for it. If successful the Camo guy can go Top Mid and jump S3 to harass the opposition into picking up the OV early.
Another player should sit on Ghey Jump and put as many shots into the person jumping from Green Lift. Basically doing the same job as the guy watching Snipe Lift. This is a very important job so have your best shot man hold this down.
The remaining players have a choice. They can either leave the Shotty for their teammate watching green lift, or one can get it, and instantly push Bottom Mid and go to Green. People will generally not expect this and it is a good way to attain Sniper control from the beginning.
A final option is to go to Top Blue, spam some nades at S2/Elbow and simply watch for any foolish rushers top mid. This is the safest option to go for, but only one guy should. And you always want a guy to do this in case the other team make a surprise push through Top Blue.
Well that is the Opening Rush for Guardian. Sorry it was so long, but it really is pivotal in setting the pace of the game and how it will be played. This section for other maps will be no way near as long.
Basic Set-upsSniper-Tower/Green.The strongest set-up you can have in Team Slayer. To make it even better, you want to have a quality sniper. The conformist set-up is to situate this sniper S2. However, I find that positioning yourself with the Snipe at Top Green is the best. The enemy do not suspect it, and you are locking down the easiest way to Break your control - Rushing through Blue WIndow/Snipe Lift. The remaining players should be positioned around S2 where they can easily channel their view to Bottom Mid or Blue WIndow/Lift.
With 4 players, it is not a bad idea to have a guy on Camo, if this player also has a grav hammer/Shotgun, they are a huge pain in the enemies side, preventing fire to the sniper, watching top Mid, monitering top Gold and being an extra gun for battle at Top Blue.
Blue/Gold.I actually prefer this set-up if I have the lead, because the enemy have to come to you in a confined place. You want to have a guy top blue, occasionally going out to Blue Window. Another Player at Gold. And another at Blue Hall. If it is 4v4, have your final guy on ghey jump to watch Green and sneaky players coming through bottom mid.
Breaking Set-UpsThis is huge in Team Slayer and is generally what you will be doing most of the time.
Breaking Sniper Tower/Green Setup.For this, you want to catch the opposition off guard so one player can make a quick lift to S3 and spam some nades down to S2/S1. Another player should push camo and try and weaken players at green so a team-mate can push through Bottom mid and pick up some kills. From this, you want the guy at camo to push top mid all the while nade spamming S2, the guy at green to push up elbow, who should also be nade spamming if possible. The guy at S3 should try and clean up kills. If you have a fourth, a good tip is to have him support the guy camo by being top gold and firing into S2 before dropping to bottom mid to support at Green or push S1. With this, you will have the enemy team spawning bottom blue, an easy position to spawn trap them in with some pre-nades and team-fire.
Breaking Blue/Gold SetupAssuming the game is a stalement, but you need kills and have Snipe control. Have your guy at Green, lift to invis (if no-ones already there from your team) and send another guy to green. Situate your sniper at S2 and have your remaining player Push Blue window. From then on, you want to establish Top Gold/Blue Control with numbers through the player at green jumping Top mid to support the camo/Blue Window Player. This will spawn the enemy at Green or elbow, the easiest place to spawn trap them in as long as your final player at S2 remains calm with people charging up elbow. Nades are your friends if you are that player.
And...that's guardian in a nutshell. I know you said you go in as a random, I know what it is like, personally getting my 50 in TS as a random. I highly urge you to either play in a team 3s/4s or play in 2s. And utilize greater communication to organize some of these simple (yet successful) strategies.