I am always in favor of having children all in one go. Not all at once, of course. A gap of one or two years between each child is fine. Just make sure the wife gets all the nutrition she needs.
There are many advantages of not having children too far spaced out. One, you save a lot on the baby things. If the gap is a few years, then very often the baby things are lost, thrown away or given away before the next baby comes along. Buying a whole new set of baby things can cost upwards of 500usd.
Another advantage is that the younger ones can take over the outgrown clothes of the older ones. Children tend to outgrow clothes faster than wear them out. That's another savings.
The biggest advantage would be that the children are more likely to grow up as a team since their age differences are not that great. This kind of sibling bonding has a lot of benefits which will manifest themselves even when the children have grown up.