For efficient government, 2/3 majority is a must or else nothing will ever happen (or it happens at snail speed). That would be detriment to a country's competitive edge as more "bureaucratic traps (or stalemates), means delays.
For a good ruling (or government), it should have a healthy set of members of dissenting views. These members should be team players, i.e. for the good of the team, discord should be settled behind closed door. Frequent deliberation of plan, policy or implementation within party will prepare ruling for whatever salvo that comes from opposition (who in my opinion, is out there to see ruling trip and fall rather than help). In politics, opposition is more of a competitor rather than friend. The instinct to see to it that ruling fail is a survival instinct. Balance and check is just euphemism for waged war to win seats at the expense of other party. No ruling party in power wants their majority less for the sake of balance-and-check; not even when opposition becomes the ruling party. To me, it's bigotry to idealise balance-and-check while both parties are constantly fighting for majority.
Now, it all depends on ruling (or coalition) party. Is there means to voice dissenting views from within, and deliberation afterwards to gain consensus (or compromise)? A healthy ruling party should have critics within and healthy dissent, while simultaneously giving the enemy the impression of formidability.