This is pretty much what I do...order my attackers based on who does the most and close out with whatever I have left...
I just used 2 TMs to make a DT/O Dragonite (was SW/HB) and may max it out since higher DPS is more important and I can use the Dnite as mostly cleanup...
I'll probably save coins for Tier 4 raids only though...They should make raid 1=25 coins, 2=50, 3=75, etc...
Raid 1 isn't worth 100 coins to buy.