The most important thing to remember is that while triggers create an ability on the stack which can be responded to separately from whatever triggered them, replacement effects alter how other effects resolve in real time
Offering bounce and once-per-combat locked card draw, Miguel OHara is expensive for minimal upside
10 Entreat The Angels Can Never Have Enough Casting Entreat the Angels normally is fine
Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.) Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.) Whenever you attack with at least two creatures that have first strike, double strike, vigilance, and/or haste, transform Path of Mettle
Better yet, you are able to choose two modes, which offers a lot of versatility for a single card