Is this article wrong/scammy? Is it possible that miner earn more by mining several different coins at once through minergate? https://ambcrypto.com/mining-in-the-bear-market-made-easy-fast-and-cheap-with-minergate/

This one claims they can mine more efficiently by mining several coins at once.

I have a hard time believing that any pool can outperform "normal" pool.

What's the story.

Is this possible? Is this guy legit?

Let's for simplicity sake we got to pick numbers from 0 to 7. Say the hashing function is add 5 modulo 8. Of course the "right" nonce is 3. That's because 3+5 is 0 module 8.

Say the hash/signature or whatever of the transaction is 1. Mining is finding an extra nonce, if added to 1, would hash to 0 (or below difficulty). Something like that right. We try and found that the extra nonce is 2.

Say we have 2 coins. Say the starting nonce is 1 and 2 respectively. I wonder if it's possible to to add extra nonce to 1, then try to find an extra nonce where the hash is 0. Turns out if we add 1 to the extra nonce, we got the right answer.

We just add all the extra nonce and got the nonce that hash to the right number for 2 coins. 

Is that possible?

My understanding of how mining works is quite a bit shaky here.

Is my understanding correct?

Is miner gate offering merge mining for coins that do not support it?
You can possible optimize revenue by switching to mining another coin dynamically, but it isn’t possible to mine two different coins in a given grind attempt.

The exception are chains which are merge-mined. Each merge-mined chain block is committed to a block of a main-chain block, a Bitcoin block for example. Validators of the merge-mined coin can validate POW of the main-chain (eg Bitcoin) and enforce separate consensus rules.

The difficulty of a merge-mined coin can be equal or higher than that of the main chain.

Therefore, if there is any significant value in the merge mined coin, a Bitcoin miner would be incentivized to include valid block commitments in each Bitcoin block it attempts to mine.