Arabs boss Jackie McNamara raided former club Partick Thistle to tie the pair up on pre-contracts.
Defender Paton and wideman Erskine have helped fire the Firhill club to within a point of the Irn-Bru First Division title and now Mackay-Steven insists they will have no trouble at all adjusting to life in the Clydesdale Bank Premier League.
The former Airdrie man said: "It's good to see the two new boys signed up already. Partick Thistle have been great in the First Division this season. I've been keeping tabs on them and Paul and Chris have been two players that have been very important to them.
"They have been impressive and we are already looking forward to linking up with them.
"Chris is a similar player to myself and he's the type of player I like to watch and like to play with, so I'm delighted with his signing, and I'm sure Paul will be great as well.
"I've seen that Chris has been scoring and they both look like fantastic players, so yeah, we're happy to have them.
"From watching the two of them play, I think they will take to life in the SPL just fine. They have both shown they have got ability and have performed so well over the last few years that I don't think they will have any problems.
"When I moved from Airdrie, it took me time to adjust but not too long. The boys here helped me massively and the new gaffer will know the lads from his time at Thistle, so I'm sure that will be a boost for them.
"There are pressures in the First Division, just as there are in the SPL. It won't be too much different for them. They will be relishing the step-up and we're looking forward to it."