Why was Titanus reused during the third season of Mighty Morphin Power Rangers?

The Power Rangers call upon Titanus again during the third season of Mighty Morphin Power Rangers to combine with the Ninjazords and Shogunzords to form new Ultrazord combinations. This is because unlike Zyuranger and Dairanger, the source Super Sentai series for the first and second seasons of MMPR respectively, Kakuranger does not have a "carrier Zord", so Titanus was reused.