For simplicity sake, break up Article 26 and Article 30. Article 30 is an additional benefit beyond FMLA leave...
Section 3. The leave afforded employees in this Article is in addition to
the leave entitlements contained in Article 26, Section 5.
The provisions of this Article shall not run concurrently with FMLA. The
employee shall determine in what order he/she will utilize the provisions
contained within this Article and Article 26, Section 5.
In theory you could take 3 months of FMLA, then 6 months of Article 30, then request an additional 3 months of Article 30.
In terms of your original question, you can use FMLA leave in any way you'd like for infant care in the first year. If you want to take 6 weeks, come back and realize it's too soon or your spouse needs extra help, you can take another 6 weeks off.
Heck, you could work 2 day work weeks, 3 day work weeks, etc to utilize your 12 weeks.
I've broken it up with each of my kids, no issue at all.