Okay then refresh the whole thing and not just a single row whenever TRR is triggered.

Or refresh the whole thing after a certain number of row activations.

Or interleave activations with refreshes. Say, after every 5 activations, refresh the next row in the refresh cycle.

I'm not a DRAM expert. They can figure it out. I promise if you refresh the whole chip after every row activation you won't have rowhammer. It'll be too slow though. Somewhere in between is the fastest point where there isn't rowhammer.