DHS has 10 rides at most. DCA has like 25. Plus it has more headliners. With more rides there is less need for FP. In general queues at DLR have a shorter wait time than at WDW mostly because there are more rides so people spread out more.
Also, as a PP mentioned, there is less space at DL and DCA and hence there is less space for adding FP machines.
Finally, wait times at TSMM at DCA top out at 60 minutes and are ofen 25-40 minutes. At DHS the wait times top out at 90-120 minutes and rarely go below 70 minutes.