Odd warmup result after shutdown followed by restart

Have 2-node cluster on Linux, and run memcachetest to insert 1M items. After rebalance, it has 2M items on the 2-node cluster. Kill both memcached, and then restart the 2 nodes. When warmup completes, I see some odd result. One node #1, it has ~54% active resident ratio and 0% replica resident ratio; on node #2, it has 0% active resident ratio and ~52% replica resident ratio. In ns_server log, I see message "Enough MB of data loaded to enable traffic" from maybeEnableTraffic(). I am not sure if it has anything to do with the odd result.

On node#2, it seems that it loaded all replica vbuckets before load stops. I am wondering whether it is good idea to load active vbuckets before replica ones during warmup.