Right-angled branches
The central trunk of a conifer allows for strong branch attachments. Wind and rain usually snap a conifer limb without damaging bark on the trunk but snow and ice can pull a very strong limb out completely causing tearing of surrounding trunk wood and bark.
U and V-shaped branches
Weeping Japanese Maple with U and V shaped unions also displaying co-dominant situations. A U shape is stronger than a V. If the branches or trunks are similar in diameter the union will be weaker than one being larger. V’s are more prone to developing and or containing included bark which makes a weak attachment and can develop decay leading to branch failure.

U-shaped branch attachment
Branch showing solid attachment (union) to trunk and swelling of trunk as it makes room for branch. No bark of trunk or branch included in union.

