Investment based on Mutual Fund for Beginners

Even though TATA ethical fund is TASIS certified. Still it has some companies which are not fulfilling all 4 criteria(as mentioned in one of video @HalalInvestmentor.). How about investing in remaining companies of TATA ethical fund which are fulfilling all 4 criteria.

Lets say TATA Mutual fund (or any good fund) has 4 companies with investment sharing like below:
A 40%
B 30%
C 20%
D 10%

Lets say A is not shariah compliant but remaining it compliant.

So what if i invest in remaining companies like below such that ratios remain same.
B 50%
C 33.33%
D 16.66%

I agree that as individual its verify difficult to maintain such ratios. But how about doing like this, if one is beginner(as their expertise doesn't match with experienced person.)