You're just making life difficult for yourself.I am aware of Ibn Baz's fatwa, however, however it cannot be argued that it applies to the nuclear family model that is practical in the West as we are clearly commanded to increase the Umma by having more children. 3 kids in eight years is very common among practicing Muslims and even some non-Muslims. The argument against having more is mainly down to Irzaqa reasons in the West which is Haram.
Having more than 4 kids in the West is not feasible for those that seek a certain Standard of Life. A childbearing female married in her early twenties will have an average of more than 4 children unless family planning comes into play.
Contraceptives are halal. You can space it out.
If you overthink things, you make things harder for yourself.