No, echoes aren't clones.
Although we need more information regarding Daisy to be conclusive, Clones were used to save time mainly in one front, while echoes are used to save time in 2 fronts.
I think that the best example for this is Marth and Roy in melee, vs Mart and Lucina in smash 4.
Yes, both reuse Marth structure, and animations, and both have a slightly modified mechanic of marth, but in melee, Marth and Roy had different stats, different porperties for they attacks, and stuff, meaning that while manufacturing the character was quicker since they reused assets, balancing teh character was literally balancing 2 completely different characters, just, look at mart's and roy's tier placements in melee and you can see that they are worlds apart.
On the other hand, while Lucina can do stuff different than marth... or at least more different than Pit/DarkPit, in the end, they are the same character, balance wise. to the point that when people started actually figuring lucina strengts, she ended almost next to marth. This means that not only manufacturing the character was made easier, but teh most important, balancing the character was easier.
And probably thats why we are getting in echoes now, for that exact same reason. Play almost the same, with maybe one or 2 very minor differences, and while almost the same stats and attacks properties, mayeb different animations. so they don't need to worry regarding balancing that +3 characters, meaning that they really are almost freebies. Visual differences, but gameplay wise, almost the same.
Lugified clones are like the melee clones (similar visuals, different gameplay) with parts of their kits altered so they differ more from their clone couterparts, and semi clones are completely original characters (at least regarding manufacture) with similar design principles that other character. (Wolf) As far as i know at least.