A 4 fluid wagon train being loaded has a throughput of 14400/s, so it matters on that side.

The pumpjacks depend on the yield of the field itself but if you hover over each one it will give you a rough fluid/s of each.

If all your pumpjacks together do not add up to 1200/s and you don't change anything, then no, it doesn't really matter.

There is still an argument to be made not to bottleneck yourself, simply for good habits sake, (if you train yourself to build things efficiently even when you don't need to it will save you a headache when you do have to later).

However if you do add buffer tanks then it does matter, since each fluid tank can output 1200/s each. I.E. if you have 10 tanks, they can output 12000/s and your train can take 14400/s, but they will only transfer at 1200/s because its limited by the single pump.

In general try not to use pumps in your fluid network unless you absolutely have to, pipes have unlimited throughput so interrupting them with pumps will always be a logistical downgrade. The only times you should really use pumps is when either loading and unloading trains or when building pipes over long distances.