I think it’s pretty common for studios to request that their candidates have working knowledge of the systems they use. Most production studios have several shooting bays and use the same camera model in each bay for consistency. Especially if they are trying to churn out bulk photography in a fast and efficient manner.
The bigger question you should be asking is why are they ONLY paying 80 quid/day (that’s about $125USD, american folks!)??? That’s an absolutely horrible rate for photographers. The lowest rate I’ve seen in NYC at even some of the smaller studios is $500USD.
Their work isn’t actually the least bit impressive either.