thou some people have sent 3 months and got a visa, your increasing the risk of refusal

at best you'll get the visa, at worse they will refuse your visa for not sending the required evidence, if your lucky they might ask you to send the other 3 months statements.

why risk problems - lose your fee and waste time and then having to appeal or re-apply

one of the main reasons for a visa being refused is because the person has sent in a uncompleted application/missing evidence, like i said if your lucky they will contact you and give you time to send the evidence, if not they will base the application on the evidence you've submitted and so your refusal risk has just increased

the embassy are not stupid, if you send only 3 months statements they know why you have not sent the others