I've seen a few posts that complain about Surge and Seeker being OP. I use both of these btw, and I'm speaking from my own experience using them and fighting them. While legendary mechs are legendary for a reason, other than higher HP, combating them is no different than any other mech. You just gotta figure out the strategy. And end game weapons will kill a mech with 280k HP just a fast as a mech with 80k HP. 

Tips on Surge: First, most surge/Nomad/Killshot players cant help but sperg their dash ability. This shows up as movment on the main screen and on the mini map and is a dead give away. Plus surge tends to move in a very fluid manner, so when you see a mech name doing little swoops and circles, you know you probably have a surge. Once you know youre fighting a surge, especially if they are a nuisance to you, you should try to take them out quickly. 

Obviously the easiest way is to just snipe them from a distance after you locate them. If you know that you cant kill them before they stormdash you, then you have to sneak up behind them. Or, what I do is just wait for them to pounce on a team mate and then I nuke them. With timing and luck your team mate should survive the attack. If they don't it is still better to take out a Surge with 1 kill than let it get 4 or 5 kills. 

Or, there are a number of mechs that have abilities to counter surge. Stun, EMP, and now Blockhorn's barricade. 

Seeker: I got Seeker because I hate campers. If youre going to hide at the back of the map sniping people or launching guided missles or mortars, you dont get to complain when I pop up behind you and cap you. 

Fighting Seeker can be frustrating at first, because odds are you arent paying attention to your mech. But you can tell when youre being targeted by a Seeker as their target shows up on you. It goes Red when they warp. You can turn around and blast them or what most people do is back up so that they warp infront of you or on top of you. This foils their attack usually and gives you time to counter or dodge. 

In a recent 5x5 tournament I was targeting a guy who was a dedicated camper. In the 2nd round, after I'd already killed him 3 times in the first round and 2 times in the 2nd, he waited for me in a corner with a Guardian and shut me down completleyt when I warped. I applauded his strategy. 

Another thing to note is that the AI bots have a 6th sense when it comes to Seeker. Every time I warp near them they immedialtey turn toward me and start blasting. Human players generally wont notice me, but the bots always know. So if you know youre figting a Seeker, hang around some bots.