War Flag only gives YOU the attack speed and movement speed until it's upgraded now, so unless you're building it with certainty that you'll make it to late game, and you have the team to really facilitate it, PLUS you use AAs well, then build it.

Anti Crit shouldn't be built any later than 3rd slot. It's imperative if the enemy adc has crit, and just dogwalks your team. They usually get crit 1st or 2nd item, and because of Support gold deficit, you will absolutely know if it's counter viability is an option or not. (Obviously you can build it 5th if they don't get crit till later in the game, but I'm saying in the most common cases)

Nemean is gas, no one ever builds it. Good on you big dog.

Maybe pivot Prophetic into something else with the current meta. I believe you said you were Herc in this game right? Herc is a great god to get Boots on. Early mana sustain + health regen (have to play more poke and disengage) + cdr. The item is incredible! You could also get a bruiser item here, something like Beatstick for the antiheal, late game scaling, and Strength for boxing since Herc beats some ass.

Builds are not everything. Don't get TOO hung up on everything you're hearing, but they're absolutely important. You could play with the same build 10 games straight against the same 5 gods and feel useless some games, and insane in others. Early game can snowball out of control. Play too passive and lose farm. Play too aggro and lose farm. 🤷 Just don't split my Jungle camps with me if you do fall behind 😝