Your understanding is flawed. Its not about isolation but priorities. And it is not just China but Turkey is getting their shares of project as well.
My understanding is sound.
I have already pointed out to you that our political leaders have no sense of strategic depth and diversifying investments; they are mostly interested in commissions and are known to award contracts of many projects to those firms who are willing to oblige them in this regard and/or other forms of irregularities, and many Chinese firms are willing to (mostly private). This come down to work ethics.
The fact this project is being delayed by japs for more then 3 years, that goes to show they are either not efficient or deliberately trying to delay due to their alliances with US and India. Plus, I dont recall them doing any worth while project in Pakistan, even at the time when Pakistan was supposedly in American camp.
Why are you blaming Japan for the lack of implementation on this project? Pakistani sources have clearly pointed out that encroachment on relevant lands was the reason for lack of progress. It was the responsibility of Sindh government to address the issue of encroachment, not the relevant Japanese firm.
Economy and geopolitics are inter connected very much. Pakistan as a state needs to ensure that the economic benefits it can offer, first and foremost go to its allies.
We need to expand the number of our "allies" then; offering (fair) investment opportunities to a large number of states is a necessary step towards this end [sworn enemies can be excluded of-course]. Our worldview should not be restricted to China and Turkey [only]. There are many states that are willing to do business with Pakistan on fair terms. Many American firms are also willing.
Our foreign trade portfolio extends to scores of states across the world [including those whom you despise]. Should all of them terminate all forms of trade with Pakistan - besides Turkey and China - how well Pakistan would be doing economically then?
No harm in doing business with Turkey and China but our leaders should strive for highest quality work under specified budgets for major projects and award contracts to the best firm in completely fair bids. In short: Chinese and Turkish firms should compete with others [in a fair manner] to win the bid for a major project in Pakistan. Exceptions can be made in projects [of strategic value] but this should not be the norm in projects for the benefit of the public.
Encouraging friendly states to invest in Pakistan is one thing (already happening); being fair in business practices is very important in its own right.
I don't think China is much behind in technology specifically in railways..
This comes down to [our] choice - which Chinese firm was awarded the contract? its level of expertise? work experience? and terms of contract?
Remember the substandard Chinese locomotives that we received some years ago? Not only that but delay in their delivery costed our railways billions in currency:
http://fp.brecorder.com/2017/04/20170405164252/
Pakistani state seriously needs to revisit its business ethics.
Some Chinese firms are willing to do an excellent job for the right price and may not compromise on their work ethics but many are not like this (mostly private firms). I know through personal contacts the real reason(s) why the Neelum–Jhelum Hydropower project experienced massive delays and cost penalties.
Conversely, Chinese government is not likely to compromise on quality of work across mainland China; they allocate ample funds for this purpose and award contracts to most capable Chinese firms for the same. Chinese members are in a better position to elaborate in this regard.