Is there a limit as to the number of statues of Jesus, Mary, Joseph, etc. that should be in the worship area of the church building?
According to Sacrosanctum Concilium, art. 125, "The practice of placing sacred images in churches so that they may be venerated by the faithful is to be maintained. Nevertheless there is to be restraint regarding their number and prominence so that they do not create confusion among the Christian people or foster religious practices of doubtful orthodoxy."
According to the GIRM, n. 278, In keeping with the Church's very ancient tradition, it is lawful to set up in places of worship images of Christ, Mary, and the saints for veneration by the faithful. But there is need both to limit their number and to situate them in such a way that they do not distract the people's attention from the celebration. There is to be only one image of any one saint. In general, the devotion of the entire community is to be the criterion regarding images in the adornment and arrangement of a church.""
Based on these instructions, the number of statues should not be excessive and the number of statues of each saint are limited to one each.
It seems to me that the limits of one image of each saint do not apply to Jesus. If so, the requirement of a crucifix in all churches would prevent any other image, such as the Sacred Heart or the Infant of Prague, from being placed in churches.