To some extent. Seal Team takes elements from actual operations and incorporates them into the storyline, but it also adds fictional elements for dramatic effect.
The action - packed plots. Since it's about a Seal Team, there are always high - stakes situations. Fanfics can take these situations and add their own twists. For example, a fanfic might have the team facing an unexpected enemy or a new type of weapon that they have to figure out how to deal with. This keeps the readers on the edge of their seats.
One idea could be that they discover they are going to be parents unexpectedly and have to deal with the reactions of their friends and family. It could be a comical situation as they are both rather unconventional characters. For example, Grim might be shocked and initially try to find a way to reverse it, but then slowly warm up to the idea of being an 'uncle' of sorts.
Billy could develop by becoming more responsible. He might start thinking about the future more seriously instead of just his usual carefree self. For instance, he could learn to save money for the baby or start looking for a proper place to live. Mandy, on the other hand, might show a softer side. Usually tough, she could become more nurturing and protective, showing that there's more to her than her intimidating exterior.
One of the most heroic deeds could be when they faced overwhelming odds in a battle but still managed to complete their objective. Maybe they were outnumbered but used their superior tactics and marksmanship to turn the situation around.