Balancing valves would sure be nice, but it's not a perfect world.
I just repiped a whole house this week. "plumber" ran everything in 3/4 after some thieves broke in. We ripped that trash out and went back with 1 1/4 BI.
Riser goes straight up, bullheads into a tee. Right feeds 5 rads, left feeds 3 rads. Same with the return. Pump is on the return.
Although not technically "correct", it's worked for years.
I would totally agree that dan is right.
Except in this charity case, we just need it to safely heat, not perfectly heat.
Textbook correct, isn't always correct for the situation.
I've never seen a "correctly" piped boiler, especially steam.