Both Shane and Ilya would definitely choose a surgical specialty.

Source, trust me bro. No, seriously as someone who wants to become a surgeon and has been doing elective rotations aside from the compulsory ones in surgical departments for a good year (has this been a good idea for my gpa? No. Do I regret it? Absolutely not, I am in fact persisting), I can confidently say those two are a better fit for surgery.

The relentless pace, the ego, the craziness, the hectic atmosphere, the orchestrated parts and choreographies you have to learn to perform surgeries with the team require a top level sport like kind of coordination, the comradery with your team, the competitiveness, the passionate maniacal energy pouring out of very pore before you have to perform a complicated procedure, the fast response and unpredictability of the the outcome, the crass changing room humour? It's a perfect fit for them.

More specifically, I think Shane would be an Orthopaedic and Ilya a Paediatric Surgeon

OrthoBro!Shane because the guy screams ortho bro and I will not accept any objection. Competitive, the jockest jock to ever jock in history, super fitness focused, addicted to protein shakes whose brain is 95% sport/prosthetics and has the weirdest conversations with his patients, because he is so entrenched in his job he has no idea how to talk to normal people about it in a comprehensible way.

Paediatric Surgeon Ilya because my guy has the slightly adhd energy necessary to be a surgeon and especially a kind of surgeon that would need to adapt and operate on various anatomical districts in case of necessity. Great under pressure, a good communicator, he is an attentive captain and mentor and therefore he'd know how approach terrified parents and scared kids. Also, he'd totally be one of those doctors that dresses like a superhero as they accompany kids to the or.