Nope, it won't win anything more than if it were keeping his agreement with other miners, because it has only a fraction of the hash rate, and can hence only provide just as many blocks as it would when with his peers.  In other words, that pool is betting on making a very short chain, with much less PoW than the rest of his peers, and breaking his agreement.

In other words, if this pool has 10% of all the hash rate, when his peers have mined 90 blocks on the new chain, he will have mined 10 blocks on the old chain.  Most merchants and exchanges will not see their transactions on this small chain because the blocks are too full.  So merchants and exchanges would still be locked out of bitcoin for 90% - while they would be running entirely NORMALLY if they simply upgrade their node to the majority hash rate of the miners' rules, and see all their transactions.

And as I told you, you are now considering a hard fork, so in the end, you are considering the power game of a hard fork, not the power which you pretended, came from full nodes, so you are now building an argument for a statement that is not what you pretended.  But moreover, who is going to bet on this small chain with less PoW ?  Who is going to be confident in the transactions on this short chain with minority hash power ?