The next comet lander will definitely be better designed.
Before the Rosetta mission, our knowledge about comets was very limited. When Philae was designed, the engineering team had no idea what they would encounter. No probe ever got closer to the nucleus of a comet than a few 100 km (The Deep Impact craft crashed its impactor into comet Temple-1 after the launch of Rosetta), so any theories about the properties of the surface were just speculation.
The data from the Rosetta mission, especially those from Philae which were collected despite the problems, will likely tell us much about how the surface looks and thus allow the team to design a more reliable anchoring mechanism.
Additionally, Philae didn't work completely as designed. The probe had an upwards facing thruster which was supposed to press it against the comet during the anchoring. This thruster didn't work for some reason which still needs to be figured out. Now the engineering team needs to find out if that thruster would have made the landing successful and depending on the result either remove it from the next design or prevent it from malfunctioning.
You might have some ideas how a lander for unknown terrain could be designed, but keep in mind that space missions have some additional requirements for equipment which can make a lot of designs infeasible:
- The lander must be light: Any additional gram of mass makes the mission more expensive
- The lander must still be sturdy enough to survive acceleration during the launch
- The lander must survive years in a vacuum and high-radiation environment. The latter is a problem for off-the-shelf computer components. As a result a space probe often has a lot less processing power than you would expect from an earth robot. The CPU on Philae runs at just 8 MHz!. That's likely much too slow for the real-time calculations the Cubli robot has to perform to balance on a tip.
- The design must be as simple as possible to avoid potential malfunctions of single components to ruin the whole mission. Looking at the MorphHex robot, it must have dozens of servomotors. Just one of them failing could make the whole robot inoperable.
- It must not use much energy. Electricity is a very limited resource on space probes.