Solskjaer is doing well against top sides because defending deep and counter attacking suits current United side. When the onus is on United to dominate and create against lesser sides, MU are struggling. He did well against Lampard on both occasions tactically, it reminded me how Mourinho used to approach games against quality opponents, well-organized defensively and the idea is to nulify the strengths of the opponent rather than trying to push forward, impose themselves and dominate games. It's a different form of control and Ole managed well both times, while Chelsea's 'attack first' approach failed.
Still, I prefer what Lampard's doing because it seems he has an idea of how his side needs to play and is trying to implement it with various success, given the circumstances he finds himself in. Frank's taking risks, sure, and he has setbacks, but the side is progressing, that's what gives me hope. It's a long season, we're still under transfer ban and young players tend to be inconsistent so who knows how things'll turn out come May, but the mood around the squad is very positive.
With Ole, if he spends a bit more and brings some quality creative players to United's midfield,I guess we may see from him a different, more proactive approach to games. Perhaps he feels given the squad he inherited current playing style is the best way to get points on the board. Also, he is probably under more pressure than Lampard at the moment.