Short answer, yes you can.
Long answer: The purpose of discovery is to gather information to build your claims or defenses or to challenge the other party's claims or defenses. As such, each side will likely need to ask for different things during discovery. The are limits to the number of discovery requests you can make, and if you waste them asking for things you do not need, you might not be able to ask for things you need later.
It is unlikely that the plaintiff and defendant want to know the same information for the trial; therefore, it does not make sense for a defendant to simply copy the plaintiff's discovery request. Those "easy questions" that the plaintiff asked could be setting you up to lose the case even before you get to trial, but they might do nothing for your claims or defenses. You need to be asking for evidence that will build your counterclaims or defenses. Discovery is not something you just fumble though; it requires thought and planning. You need to talk to an attorney, even if it is just for a free consultation.