M4 in ipad Pro and m4 macbook pro only differed by 1 CPU core. Both have 10 GPU cores.You're not considering the base MX chip in iPads and iMacs are the binned versions with fewer CPU / GPU cores, while the base MX chip in MBP is actually not binned and has the complete cores, you have to sum 10-20% to multi core and GPU in that comparison, as I said, it enters base / binned M4 Pro territory.
The actual numbers will more likely resemble something along these lines:
non-binned M5: Single core 4133, Multi-core 18500, GPU 90000
base (binned) M4 Pro. Singles core 3900 , Multi-core 20000, Metal 97000
The CPU core difference was worth about 800 geekbench points.
M5: Single core 4133, Multi-core 16250, GPU 74500
Plenty for diffentiation.