I thought although possible, replacing batteries on iPad is not that simple compared to an iPhone, and thus it's better to just replace the whole unit.
I remembered going with a friend to an Apple store in Singapore as she wanted to replace the battery of her iPhone 6. Even for an iPhone, the genius ended up breaking her screen. Lucky for her she ended up with a refurbished unit (and she was happy as it was practically like new) for the price of a battery replacement. I don't think these technicians would suddenly be an expert in removing iPad screens. Or maybe Apple have new tools for them?
Personally I would rather just get a whole replacement unit. Better than risking the tech breaking something else.