The introductory rites: one of the battlegrounds of the liturgy tussles. DMC weighs in on the side of directness and simplicity. The important factor is to allow these rites to do their job and not distract children.
40. The introductory rite of Mass has as its purpose “that the faithful coming together take on the form of a community and prepare themselves to listen to God’s word and celebrate the eucharist properly.” [GIRM 24.] Therefore every effort should be made to create this disposition in the children and not to jeopardize it by any excess of rites in this part of Mass.
It is sometimes proper to omit one or other element of the introductory rite or perhaps to expand one of the elements. There should always be at least some introductory element, which is completed by the opening prayer. In choosing individual elements, care should be taken that each one be used from time to time and that none be entirely neglected.
For a weekday Mass, I’d say four are enough. The entrance hymn, the greeting, and the opening prayer for sure. Add either a penitential or sprinkling rite. If after the greeting, the presider insisted on introductory remarks of any length, I’d consider omitting any other ritual and going directly to the opening prayer.