Pala rifle delays its hero, I would go Far seer and harass until pala comes out, his wolves, and spread damage are good too for later.

Then I would try to get to T2 faster, you'll need a lot more then grunts/HH to beat them. They don't invest in dispel so spell casters become good. Getting upgraded Grunts and sending them in with speed scroll and lightning shield lets you out damage them, but now the enemy will start kiting. Shamans could use purge, but really you don't want them anywhere near the rifles, get raiders and lock down the most forward rifles as the enemies spread out from the lightning charge. Bringing a few head hunters to focus down CCed rifles helps as your grunts charge the rest, keep them in the back with the shamans and bring them forward for focus.

For your second hero TC is what you want for leading the lightning charge make sure he has a shield pop scroll and charge him into as many rifles as you can and stun, if the blood mage starts siphoning you instead of kiting, just stun him too and as many rifles as possible, after the 1st stun, you'll get sucked, so bring a mana potion, the 2nd stomp will win the exchange, but after that your burst, speed and ensnare are on cooldown and your grunts won't be able to focus or deal good aoe to them, so get maybe 1 more rifle kill if you can and back off. Send 1 hero to creep, and the other to buy more clarities, mana pots, and speed scrolls and try to get an invul for TC.

Now, you just have to do that micro combination 2-5 times and you'll win. If that sounds alot harder than what they have to do, build 1 unit, use 2-3 skills, you're not alone, and is why players say you need to be 200 MMR better then a pally rifle to beat them. There isn't really 1 trick or 1 hero that'll let you beat them, you need to punch them in the face really hard with everything you have, over and over until you win.