Doug McCrae
Legend
Yes. Not only that but you don't have to use 5*level 1 monsters in every encounter. You could use 3*level 5 for instance, which is only slightly more powerful (600xp total versus 500xp).Thats a non starter for me, the DMG I think its in, has a guide to scale down monsters which works within 5 levels of scaling so you can use any monster up to level 5 possibly 6 scale it down to 1st, you could also scale down level 7/8 and use level 2&3 monsters
Combine that with the scaling technique you mention and you can be using monsters from level 1 to level 11 against a 1st level party, more than a third of the whole MM. This in fact is what I'll be doing for an upcoming campaign. So you're definitely not forced to use goblins and kobolds at level 1. You can put level 1 PCs up against scaled drow, trolls, gargoyles, minotaurs or wyverns.