Fowler wanted more than the Ram's wanted to pay for him. Fowler wanted to be paid like a top DE, not an OLB. He also showed last year how limited he was, i.e. when asked to drop into coverage he struggled. This limit's the DC's ability to disguise the rush as the offense isn't completely certain who would be coming and who dropping. In that regard, Samson has shown himself to be an outstanding SAM, the best on the team. With Floyd not only do they save money but gain a more versatile player capable of a high-level rush, and still able to drop into coverage.
Littleton is like Fowler a much too limited player to allow the DC to disguise rush and coverages. He lacks the speed to play anything except zone. It was clear to me from his struggles in man coverages that they probably would allow him to walk. Again it was a matter of cost and reward. With Young, Kiser, Howard, and Reeder they have excellent speed and versatility at ILB. More than they have had perhaps ever. Offenses won't know if the coverage is zone or man so early down passes are not a foregone conclusion. Littleton is a good ILB but limited in how he can be used.
NRC showed in the NFC Championship game why they didn't exercise his option. He's undisciplined and is more concerned with making a splash play than playing the scheme. No DC will tolerate that except perhaps Phillips and most would have benched him in 2018. If you can't trust your DB to play the scheme no matter how good he is, you can't play him. NRC thinks he's better than he is. Williams clearly outplayed him last year. I expect Darious Williams to be penciled in as the slot CB this year and think he will be just fine.
Personally I like the moves or at least understand them. I'm sure the Ram's would have worked around Dante's limitations but not at the price he was expecting.