In international relations the equality of the rank is observed rigorously unless both sides agree on “upgrade”. E.g. China’s Foreign Minister Wang Yi met last time he was in Moscow not only with his same rank–Sergei Lavrov–but he was also invited to Kremlin and met Vladimir Putin. But this is normal. By far the more interesting “upgrade” is this:
Putin meets Chinese defense minister, hails military cooperation
Obviously, hailing “military cooperation” is a mandatory diplomatic dance and press-release fodder, but when defense minister of China meets President of Russia and not just his counter-part Sergei Shoigu, it is very clear that very large issues are being decided upon and we may even guess what those issues are.
Recall those two meetings in March, a four and a half hour conversation between Putin and Xi, and the next day meeting behind closed doors of Russian and Chinese groups heavily dominated by military and military-industrial complex people. Li Shangfu’s visit is precisely about those two meetings, or, rather, practical continuation of those. Otherwise he wouldn’t be meeting Russia’s President. Moreover, Li Shangfu is in Moscow on invitation by Sergei Shoigu. China’s MoD went on record prior to this visit:
“New progress has been made in strategic communication, joint exercises and training, and pragmatic cooperation,” Chinese Defense Ministry spokesman Tan Kefei said Friday. “These have continuously enriched the strategic connotations of the China-Russia comprehensive strategic partnership of coordination for a new era.”