Yes, transaction conflicts caused by updating the same data simultaneously on different clients is unrelated to how many alphas you have. Transactional databases (dgraph, postgres etc etc) will see that two edits happen to the same data concurrently and intentionally causes them to fail, as the result might not be deterministic. You can disable this with @noconflict.
RE adding more clients, it will improve speed up to the point that dgraph is under full load already, then it will not help any more. At that point you need to either scale dgraph, or make the transactions themselves more efficient via batches.