Authors reported perplexity only for small up to 3B weights models. On the other hand, they reported throughput for 70B model, but not its performance (perplexity, end-to-end tasks). Very unfortunate omission. Overall, the paper is rather poorly written.
If I understand the authors correctly, they trained the compared models on only 100B tokens, all drawn from RedPajama, to make the comparisons apples-to-apples. That's sensible. It allows for easier replication of the results. Otherwise, I agree with you that more extensive testing, after more extensive pretraining, at larger model sizes, is still necessary.