English Translation
Or rather it seems, Kensuke arrived at the studio at the same that I and the other two were still coming.
This is a very problematic sentence.
- {{健介}} shouldn’t be a cloze-word. It’s a male first name and it can be spelled in Kanji in hundreds of ways such as 謙介, 謙佑, 賢介 etc.
- The English-Japanese pair doesn’t match. The Japanese sentence means “Well, Kensuke and I probably arrived at the studio at the same time, but two other people were late.” But the English sentence says the other two guys PLUS I were late.
- The Japanese sentence is even grammatically broken. Don’t use まだ + 遅れている. まだ is “still” or “not yet”, so it means “the two other guys were trying to catch up with Kensuke and me, but they were still behind us”. まだ + 到着していない / 着いていない (= have not arrived yet) is the correct collocation.
- ってか is a highly colloquial expression whereas 様だった is for a formal writing. みたい is relatively casual and a good match with ってか, but we don’t use みたい and 様だった (both mean “seem to be”) in the same sentence.
FYI: the Japanese sentence was originally sourced from Tanaka Corpus (田中コーパス), and then adopted by a native Japanese speaker mookeee. I sometimes found mookeee’s adopted sentences unnatural.