Match the use-case: choose poblano for roasting/stuffing, bell pepper for sweetness without heat, and jalapeño/serrano for recipes that tolerate extra kick.
Use the listed ratio (1:1, ¾:1, or ½:1) as your starting point, then taste-test after cooking if your dish relies on pepper flavor.
If using a hotter pepper (serrano or jalapeño), de-seed and roast or quick-simmer to bring flavor closer to anaheim.
For bell pepper swaps in baked recipes, add a pinch of smoked paprika or chili powder to restore anaheim-like roasted depth.