Sure, and a clever enchanter can do just that, piling up multiple spells, each step individually reasonable in itself, but getting stranger and stranger by the minute.
If you have enough suggestion spells to use, of course. And if the enemies don't make their saving throws. Every spell is another chance for them to roll high, and even Bozo the Drunk Wisdom-Dumping Ogre can still roll a nat 20.
It's more efficient to use the first spell to get them do what you want, but there might be situations in which, say, "Drink this bottle" might get a +2 circumstance bonus on the save, while, "I'm an honorable enemy, sit and talk with me" followed by "Aren't you thirsty after talking so much? Here, have a drink" might not. Or maybe the suggestor is in public and doesn't want to tip his hand to anyone listening.
Now, if you have two conflicting suggestion spells, I'd probably say the later one takes priority, but that's very definitely a GM call based on the nature of the suggestions. Bonus points for a clever PC who role plays it out up with a crazy way to fulfill both at the same time.