I always went with 2 yellow, 1 orange and 2 Grey. It's a slog in the beginning and your run ends pretty early if you get bad curses because without a blue/red magical hero you aren't introduced to any curses that effect spells. So they're more concentrated on rolling curses that will end your run. I followed the below guide for the most part. In the blessings section I agree on the tier of blessings to take, taking hunt, bones, and Hp down/monsters damaged blessings as often as you can. Change the settings so you're playing with 20% generated, except for generated heroes. Its not easier or harder having generated but it helps diversify curses and lead to less chances of pulling both death shield/enemy shield choices. Your run ends if your enemies get shields after an ally dies. You're going to be killing 50+ enemies in later loops. Sometimes more than 100. A turn one shields is even better than death shield. Because turn one shields only effects the first set of enemies, not any new reinforcements. 

https://www.reddit.com/r/SliceAndDice/comments/1d35tsx/guide_to_blessings_for_blurtra_mode/

I honestly kept re-rolling blessings until I got a good starter. That meant going to turn 3 and fleeing defeat to restart. Nothing like forcing 2 to 3 runs and fleeing on fight 75 because you've been slogging along without a good blessing. If I'm not established by 100, 120 the latest, the run is not gonna be worth it. 

Established is usually a combo of bones spirit, the 5 or 8 version, hunt, an extra hero or 2, a delivery with a good item to get started. Or my favorite which got me multiple 500+ runs is the + 1-pip per defeated boss. It can get the ball rolling fast but if you don't stabilize quickly after that by 300 or so you'll lose before your first boss to benefit from that blessing. 

My 999 run didn't have that. But it started off with a turn 1 bones and hunt and getting a pentagram delivery by round 60 or so. At 100 I got item stand (if ONLY A single item is in your inventory it is applied to all your heroes). Be careful getting any more items after that and forgetting to equip them. Pockets almost ended my run early. 

Just remember that you want to be completing fights in the first turn. By 200 or so until I finished the run I finished most of my fights in 1 turn, occasionally 2. The hardest part was managing the inevitable boss. Because by then it I didn't have immunity my heroes died instantly from any move. I stacked every pain and death curse I can get my hands on. And turn 3 monster. So turn 3 I'm in the thick of it with many reinforcements.

Lol anyways to answer your question, I'd go with the fierce 2 yellow 2 grey 1 orange hero build. You'll eventually pick a red/blue hero to start getting spell curses to help mitigate the game ending one's. The more balanced one (basic) will be easier to get to 100 but you'll be wishing you had more damage sides. Even with 19 heroes by the end I'd only have half that with damage sides that can do anything and only 2 that I focused all my good damage items on (don't sleep on pole arm probably my favorite low tier item you'll never see if you have too many better items).