The results of the 2012 F1 championship seem to suggest a pretty average team? Many retirements, consistently in the mid table and very much a gamble. Granted Merc were investing heavily but the results weren't exactly indicative of a team on the cusp of multiple world titles. Hamilton was also leaving behind a capable 2012 McLaren.
Bringing this back to McLaren Honda, I'd love them to turn it around in a similar vein but I've no confidence they ever will. They haven't won a WDC since 2008 and are about as inconsistent as you can get for a large team. When Alonso went there I hoped that it would fall in to place for him but it hasn't
The point is they WEREN'T investing heavily in 2012. In 2009 the team had something like 70mil to do the whole year, hence zero development. It was a bodged car, the car itself was a joke, it just had one trick no one else had. When everyone else had the trick it was a midfield car with no personnel and no budget. Merc bought them but they didn't spend £300mil in 2010, or 2011, or 2012, or 2013. They spent something like £110 in 2010, like £150 in 2011, etc, etc. I forget the actual numbers, they weren't going to be competitive in 10-13, they weren't going to win, they weren't spending big. They were spending more like a midfield team.
They could have gone 300mil on 2010, but from where they were that meant hiring EVERYONE that was available, that meant rushing into substandard facilities and that meant no cohesive plan. Instead they decided lets own the new regulation period. They brought in people slowly, bringing in the right people rather than just who was available. They brought in a smaller number each year which let them integrate, they had a long term plan, built up facilities, built up the staff and put the right people in the right places.
This was obvious from the outside because much of it was stated by Brawn, they were focusing on 2014, they were building back slowly, etc. They did literally everything in terms of building up perfectly. Had they thrown 300mil at the team in 2010, they'd be a much worse team today. They wouldn't have waited for the right people available so they'd go with others, then that role would be filled and they wouldn't have picked up that other guy they wanted to wait on, etc.
2010-2012 results are only relevant in context, and that is they were building up, weren't spending a patch on Mclaren/Ferrari/RBR at the time and they were purposefully building slowly.
This was the big difference, Mercedes had an extremely intelligent, sensible and positive long term plan, Mclaren had nothing. There was no outwards large change, they fired another guy under Ron, to get a new guy... under Ron, when it was Ron making the wrong decisions the whole time. Nothing changed, they weren't firing half the staff and building up over a few years into a new Mclaren. Where Merc were heavily investing for 3 years on a new engine, Mclaren signed with Honda on a massively rushed development, another sign of Ron Dennis. Demanding the impossible for no reason at all, not an intelligent decision, they didn't, like Mercedes, go hey, we can't just buy competitiveness in 18 months, lets put a 3 year plan in place, lets get in a top team builder and identify what changes need to be made. It was just Ron Dennis being Ron Dennis, he had an idea, it's nuts, but he does it anyway despite the obvious diaster he's walking in to.
Being 'average' when their plan wasn't to win the title at that stage isn't a bad thing. Being average when you're spending 300mil a year and want to be winning a championship is bad. Mclaren were bad by being average in 2013/14, Merc were simply building up in 2012 with no intention to win the title, they were where they should have been.