So if you have fewer creatures than the support number, youd just place the +1/+1 counter on each creature you can
A 3/3 with trample is still pretty good value for only three mana
That includes colorless creatures, enchantments, artifacts (mainly equipment), and most nonbasic lands, excluding those that generate a specific color of mana, like dual lands
Archfiend Playtime X TRAP Special Summon 1 Level 7 or lower "Archfiend" monster from your hand or Deck, or if you have an "Archfiend" Ritual Monster in your face-up Extra Deck, you can Special Summon up to 1 each of "Royal Archfiend", "Duke Archfiend", and "Highness Archfiend" from your hand and/or Deck instead
There is of course precedent for re-releasing classic cards as part of an anniversary collection
If you are building a deck around the crew mechanic, these are the ones to know