Query (Rich as they are, I think they shouldn't do that.)

English as a Second Language English Vocabulary, Grammar and Idioms
1

Hi, please have a look at this:

Rich as they are, I think they shouldn’t do that.

=> Does the sentence sound natural? or should we omit the phrase “I think”?

Many thanks
Nessie

2

I don’t feel there is any necessity to rule out ‘I think’ but of course it can be taken away.

3

The sentence is natural with or without “I think”. Inserting those two words just softens it to mean, “In my opinion they shouldn’t do that.”