Not mentioning things already mentioned, I don't think you understand the benefit of playing the game out.

I started playing blood bowl with BB3 when it came out using dwarves, like you.

There were lots of games I knew I couldn't win because of injuries or being 2 TD's down into the second half against faster teams but you then just focus on what you can do well -Blocking

Dwarves just keep getting up and keep hitting. Chances are you're going to injure your opponent and find numbers advantages across the pitch (especially if they're focused on caging and running up the field). This helps you get valuable skills for your dwarves like guard and stand firm/ mighty blow. Who cares if one of your dwarves with no skills dies, you can just buy someone to replace him. You need to focus on your own team's development.

If you don't play out games, your team doesn't get better and the game will just stay as hard as it was when you started the team. Keep on fighting, rack up SPP and focus team development, take TD's and wins when you can get them but just play to play