Suffering with new MM

no, just you

A bit of both

I think you're doing pretty well for the total number of matches you've played (assuming your total victories is fairly representative, as well as your player level). Damage over 300k with fewer than 100 total weapon levels is pretty good. Win rate in the neighborhood of 50% means you're competitive and generally winning as often not. It looks to me like you're getting placed in competitive matches and doing alright.

If you're disappointed by not winning most of the time anymore, I'd say get used to disappointment. This is a PvP game and other people aren't generally inclined to just line up and lose on a regular basis, so it's not in the business interests of any developer to enable you to choose "playing down" against weaker competition. That's why the MM changed, and why the trimag gep is no longer a formula for getting seeded against mostly people with slower bots that can do less damage. Also, the low-level geps were nerfed in HP at the same time so they no longer have the same HP as those slower, lower-damage bots you were mostly facing before.

Assuming your disappointment centers around no longer winning 3/4 of the time just because you paid real money for a Gepard (which used to be overpowered for the way the old MM handled it), I'd chalk it up as a learning experience for how pay-to-win games work. P2W companies convince you to buy something that gives you an advantage for a short period of time, then they change the game mechanics so you'd have to buy something else to get the same advantage. In this case you'd need to buy enough gold to acquire and upgrade a triple-trident Fury to dominate the current meta. Once Pixonic determines that the game has become saturated with TT Furies, they'll nerf that build and make something else overpowered so that people who are willing to pay money to win more easily will give them more money, while people who aren't paying to win will be motivated to produce more "content" for the paying players while grinding lots of matches for gold.

If you're really just confused by no longer getting unusually great returns in a PvP game and sincerely want hangar advice, I'd say it looks like you're on a good path and performing right around average (within 1 game of a 'perfect' 25-25 record over your last 50 matches, which is feedback that you're being seeded fairly). Everything in your hangar can be effective. At this point you can see which of the 4 medium bots you most enjoy playing and which you find to be most effective for your playing style, then let that be your guide for what direction to continue your hangar development. The only other thing to maybe try out is a mid-range setup to see if you like it... maybe pins on the Patton for a minimal investment of Ag. Long-range setups don't really work for medium or light bots IMO, so I wouldn't waste resources experimenting with long-range until you are running more heavy bots. Also, long-range tends to suck when soloing so maybe not worth experimenting with until you are running in squads regularly.

Your whole team consists only close range glass cannons, they can beat light and medium bots but lack the firepower and/or health to deal with heavy bots (except boa).

Consider of replacing Vityaz for a Leo, you lose some speed (32 instead 37-38) but gain lot of health 155k instead 104-111k and you can apply another pinata, much better silver option for a knife fighter until you can buy premium bots.
I also suggest to try Griffin it's slow and has mediocre health however the jump ability give excellent offensive or defensive tool to compansate that. You could equip it for mid range (Pin-Pin-Tulumbas-Tulumbas) or close range (Magnum-Magnum-Taran-Taran or Pinata-Pinata-Orkan-Orkan). This big chicken is the best silver bot available.

If you dont want to change your hangar, then change your play style. Do not fight one on one except the enemy is wounded. Support your teams knife fighters, try to ambush the reds and use the corner shooting ability of golem and boa.

Here is what I will suggest:
Buy a Pinata Thunder Leo to replace the Pinata Vityaz.
Get a Pin Tulumbas Griffin to replace the Pinata Patton or a Trident Tulumbas Pin Golem.
Buy 3 more Orkans. As for now, Get a Griffin and put 2 Pinatas and 1 Orkan and 1 Tulumbas on it.
Buy another Griffin and put 2 Tarans and 2 Magnums on it.
Keep the Boa and level it.

I wouldn't bother investing in anything new right now. Just play for a bit with what you have and see if Pix manages to get things settled. In terms of upgrades, bring the weapons on your Golem and Boa up to 7.

If you decide you want to go the heavy mech route, then do it all at once and get 4 new level 6 bots that can make use of the weapons you have available. Don't be misled by some of the other comments - none of your current robots are really suitable for the higher level environment. Investing in them is ultimately a dead end.

Not horrible advice, BUT, Griffins definitely have a learning curve and are kinda squishy at level 6. Definitely recomend starting out with 1 or 2 (pdb and rdb) and getting good with them instead of going all in. Leo's and Boa's are straight forward bots that do ok in higher levels but not top tier.

Leo with mags, rockets or aphids will have a long enough life to be worth investing some energy in. Griffins are even better, though. The Boa is a poor investment now, even though he was great back when there was a midgame and is a sentimental favorite of many players.

Wow, now we are talking.

Great amount of advice guys, thanks a lot!

I'll sleep on it and try to decide my new strategy. All I know for sure is that I can't continue with this hangar, it's not as effective as it was before.

A while back I did an all patton hanger (freshly bought no less). 

Hanger monoculture might not be super effective but your going to learn to drive the hell out of one bot. I think that the harsh learning curve of the griff would be easier to get over if you had ONE thing to drive. 

I'll take all that in consideration, but what do you think about saving WSP for a few more days and replace my midrange Golem with a Trident Carnage? While a save gold for a Galahad (will use my 2mags in Vityaz and my Orkan from Boa (replaced with Tulumbas)).

Driving the all Patton hanger got boring, but I learned to drive the hell out of the one bot. I see good grif pilots and terrible ones, and on rare occasion ones who dominate, simply because of how they drive, not their weapons or their levels. Did driving one type of bot make you a better pilot/driver of said bot?

Do it as soon as possible, but buy the 2 Tarans then a Trident for a Pin Tulumbas Golem.