Wall layer made up of many pieces?

Have a chance to get many plywood recycled boards of 15mm thick. The measure 1340 x 1120. Now at 450 centres, I would have to trim these to 900mm or so each so that they but up against each other on a stud each time. With walls that are 6000mm long x 3650mm wide x 2700mm high, this will mean each Wall , at two 15mm layers per wall, will be made up of many many separate pieces of plywood. I would run one layer vertically and the next horizontal. Of course the gaps between the many separate pieces will be well caulked. This represents much more work but much less dollars. My concern is isolation I may be sacrificing by using so many separate pieces. Would there be any negative effect making a wall layer up like this? If so, I'd rather pay extra for the standard larger sheets. Thanks.