Using an FPGA over an Arduino
Your sensors seem to provide a timed pulse representing the measured value. In case of a micro-controller, this signal would trigger an interrupt, and the interrupt handler would use a timer to measure the pulse length and store it to a variable.

In case of an FPGA the equivalent of such variable would be a counter with enable signal connected to the output of your sensor. A positive pulse would start the counter, and once the pulse ends, the value of the counter would be used by the rest of the logic pretty much the same way as a variable.

For a small number of sensors there is no real benefit of using the FPGA which will cost far more than a micro-controller. However, the micro-controller only can handle a single task at a time, so adding more sensors will make the pulse measurement less and less precise. FPGAs could easily handle as much sensors as they have free pins (hundreds to several thousands).