The Galaxy M51 is currently thought to become the first Samsung phone that breaks the 6000mAh barrier on its launch. It may have appeared on Geekbench 5 ahead of this event, in which case its SoC and RAM may have been spilled. According to this new leak, it gets a 4G/LTE-only mid-range Snapdragon chipset.
https://www.notebookcheck.net/Samsung-Galaxy-M51-a-new-leak-may-help-confirm-some-specs-ahead-of-its-launch.489283.0.html
I think the reasoning for guessing SD 675 on basis of "sm6150" is incorrect. By that logic, even the A71 launched in 2019, should (https://www.gsmarena.com/samsung_galaxy_a71_pops_up_on_geekbench-news-38954.php) have SD 675 but it clearly has (https://browser.geekbench.com/android_devices/samsung-galaxy-a71) a SD 730.
Also, the Geekbench score of M51 of Single-534/ Multi-1734 is unusally high for SD 675, actually it's even higher than average (https://browser.geekbench.com/android_devices/samsung-galaxy-a71) SD 730 score, so obviously it's running a 7xx series chip most likely SD 730/ 730G or 720G.
I think Notebookcheck should consider my sources & update the article to correct it, if the logic proves right.