Lawful immigration to the us is a long, costly and difficult process, especially for the employment-based (EB) immigration. The typical path starts with an H- or L- visa, which goes to the permanent residency and then only after 5 years one eligible to apply for the US citizenship (unless married to US citizen or serving the armed forces).
Please, see if it is possible to do one of the following for the qualifying applicants:
1) Reduce the continuos residency from 5 years to 3 years
2) Count H1B employment time towards the naturalization requirements
3) Make visas for permanent resident spouses available immediately, as it is for US citizens