It's definitely a simple kata, but could be one that allows users to explore various solutions if they choose.

If it's a simple kata, then it can be rated accordingly. Some users may find benefit in repeating this one multiple times and trying to improve their sort/matching methods with each iteration. I don't find this kata's difficulty as an, 'issue.'

In the Go translation, the argument repititions is spelled incorrectly, it should be repetitions.

The Go translation doesn't correctly start with package kata and the sample tests don't work but the official submission does

Test Results:
Build Failed
STDERR:
# codewarrior/kata_test
./kata_test.go:9: imported and not used: "codewarrior/kata"
./kata_test.go:13: undefined: multipleOfIndex
./kata_test.go:14: undefined: multipleOfIndex
./kata_test.go:15: undefined: multipleOfIndex
./kata_test.go:16: undefined: multipleOfIndex
./kata_test.go:17: undefined: multipleOfIndex
./kata_test.go:18: undefined: multipleOfIndex

Go doesn't use snake case variables or function names so duplicate_count should actually be duplicateCount. Also, the input argument is s1 but should really be s as there's no s0 or anything along those lines.