Good way to balance storage tanks?

[plush vortex]

So, I want to make a simple train loader for fluids. I have the attached circuitry to balance both storage tanks.
It works, but I have some concerns:

1. Does this create lag? I could see it having some performance issues...
2. Is there a simpler way? I want them to be equally full all the time.
3. Can I make it smaller?

[lapis heart]

Connect them with a pipe

[summer cedar]

Balancing fluids is not really ever necessary
And you could remove all the circuitry there and it would balance

Tanks connected with pipes won't perfectly balance but it's good enough

As for your lag concerns
Are you having lag issues? If not then stop caring

Unless youre going for thousands of spm it never matters

[plush vortex]

Is there some fluid / m where it starts to matter? Besides trains having to come in in under a few seconds, when should I start balancing with circuitry?
And I'm guessing lag won't be an issue for 10k spm, right?