If possible yes. The main reason for this is because context-switching is expensive. If you have to work in multiple languages (and maybe even in multiple IDE's) then for one feature your team might be switching back and forth between tools and languages. Each switch will cost time, certainly if one of the languages is only used once in a while.
Being proficient in a programming language is hard, being proficient in multiple is even harder. The less you need to switch thinking the better. Also you might not fully use the features of the second language and create shortcuts just to get it working and be done with it.
There are good reasons to introduce extra tools or languages to a project, just make sure you weigh the cost of context switching, learning curve, motivation to learn (mainly from developers) and added complexity for new-comers to your project.
Working with developers:
As test engineers are often the lesser coding gods, being able to utilise your lead developers to assist with good coding practises on the test automation is must in my book. Therefor make sure you pick your test automation languages with them together.
I would be really careful with introducing an extra language as testers into a project if you expect the developers to run, maintain and extend tests as they are adding new features. Just make sure you introduce testing tools with a whole team approach.