Thai will not be a serious "competitor" on the CPH
route. A majority of the well over one million pax/yr are business travellers even when they go on Y class.
What they require is morning and evening departures, on time, not the Thai noon departure. And they require extra capacity Sunday evening, Monday morning and Friday evening. The roughly 25 daily SAS and Sterling departures with MD
-80s and 737s can deliver that, Thai can't.
Sterling is the low cost operator. But I wonder how successful they are. In my company it is a rule that we must use Sterling whenever possible. Many colleagues have flown Sterling only once. It is simply not attractive to stand in a check-in queue for three quarters of an hour for a 40 minutes flight, when SAS does it in right away. So we find ways to bend the rules.
Sterling is mainly a charter company. They haven't learned yet that scheduled short haul is a different business which requires punctuality and fast and reliably check-in and baggage retrieval. They just treat the pax as charter pax. Thai can hardly do it much better, probably much worse when using a 747 monster ship on a 350 miles route. Which can easily be two hours late if it encounters headwind from Bangkok.
Thai can probably not even be a serious competitor to the trains, much less the very comfu 1500 pax nightly boats between the two cities.