Youthful Knight is a 2/1 with first strike, so if it was blocked by Alpine Watchdog, Youthful Knight would deal its two damage first, destroying the Alpine Watchdog before the Youthful Knight would take damage
Theres a lot of established heuristics on this subject, and a few points I can toss in to help you construct an optimal mana base for Standard, Modern, Pioneer, or whatever MTG format you prefer
I wouldn't go so far as to call this good but it is certainly appropriate
Midnight Reaper This is the weakest one of the lotbecause all it does is draw tons of cards and make sacrifice decks more powerful
Kellogg, Dangerous Mind wont warp the format or anything
The original, most popular, and most obvious way is to end the game on the turn you play Squandered Resources